Roofing Calculator

Enter your roof sections and get the roof area, the squares, the waste as its own line, and a list of shingle bundles, starter, ridge cap, drip edge, underlayment and nails, with the working shown.

Estimates for planning, not professional advice. Read the full notice.

Roof size

Roof type

Length

Feet and inches, like 12' 6"

reads as 40 feet

Width across the roof

Feet and inches, like 12' 6"

reads as 30 feet

Pitch: rise over a 12 in run

Rise in inches for each 12 in of run: 6, 6 1/2, 6/12 or 6 in 12

6 in 12

Overhang (optional)

Inches, like 4 in

Shingles

Underlayment

Starter strip

Hip and ridge cap

Ice barrier at the eaves

Ice barrier roll

Product names are trademarks of their owners. HoneyDoMath is not affiliated with, sponsored by or endorsed by these makers. Figures come from each maker's published sheets and are shown for information only.

Example: a gable roof

45 GAF Timberline HDZ bundles

Footprint, flat 1,200 ft²
Roof area, footprint times the multiplier 1,341.64 ft²
Waste allowance, its own line 10 percent
Area with waste 1,475.8 ft²
Squares with waste 14.76 squares

Estimate for planning, from what you entered and the product data shown. Check product labels and your supplier before you buy.

Shopping list

Example: a gable roof
Item	Size	Buy
Shingles	GAF Timberline HDZ bundles	45
Starter strip	GAF Pro-Start starter bundles	1
Ridge and hip cap	GAF Seal-A-Ridge cap bundles	2
Drip edge	Englert drip edge pieces	15
Underlayment	TAMKO No. 15 felt rolls	4
Roofing nails	roofing nails	3,779

Worked example: a gable roof

Show the working

Footprint times the multiplier is the roof area 1,200 ft² × 1.11803 = 1,341.64 ft²
Add the waste allowance to the total area 1,341.64 ft² + 10 percent = 1,475.8 ft²
Squares: the area with waste divided by one square 1,475.8 ft² ÷ 100 ft² = 14.76 squares
Bundles: squares times bundles per square, rounded up once 14.76 squares × 3 per square^[1] = 45 bundles
Nails: squares times pieces per square times nails each, rounded up once 14.76 squares × 64 per square^[1] × 4 nails each = 3,779 nails

Assumptions

The figures behind the example. Sourced figures link to their source below; a default is a starting value to check against your label or supplier.

Assumption	Value	Details and changes
Shingle bundles per square	3 per square^[1]
GAF's Timberline HDZ specification sheet lists 3 bundles and 64 pieces per square. It prints no coverage per square.
Shingle pieces per square	64 per square^[1]
GAF's Timberline HDZ specification sheet lists 3 bundles and 64 pieces per square. It prints no coverage per square.
Shingle waste allowance (gable or shed roof)	10%
Default A common allowance, not a sourced figure. Check your label or supplier.
Shingle waste allowance (hip roof, dormers, valleys)	15%
Default A common allowance, not a sourced figure. Check your label or supplier.
Eave and rake overhang	0 in
Default Measure your own overhang; 0 uses the footprint. Check your label or supplier.
Starter strip length per bundle	approx. 120.33 ft^[2]
GAF's Pro-Start starter strip sheet lists approximately 120.33 lineal feet of coverage per bundle (when split in half).
Starter strip waste allowance	0%
Default No waste is sourced. Check your label or supplier.
Ridge cap: length the bundles below cover	100 ft^[3]
GAF's Seal-A-Ridge sheet says 4 bundles cover 100 linear feet. The per-bundle length is worked out from this, not stored.
Ridge cap: bundles for that length	4 bundles^[3]
GAF's Seal-A-Ridge sheet says 4 bundles cover 100 linear feet. The per-bundle length is worked out from this, not stored.
Ridge and hip cap waste allowance	0%
Default No waste is sourced. Check your label or supplier.
Drip edge piece length	10 ft^[4]
Default Englert's info sheet lists 10 ft lengths; other makers may differ.
Drip edge lap between pieces	2 in^[5]
Default The 2021 IRC, R905.2.8.5, gives a lap of not less than 2 inches.
Underlayment roll coverage, as printed	408 ft²^[6]
TAMKO's brochure lists a No. 15 felt roll as 36 inches by 144 feet with a coverage per roll of 408 square feet. The coverage is used as printed (net).
Underlayment waste allowance	0%
Default No waste is sourced. Check your label or supplier.
Nails per shingle	4 nails^[5]
Default The 2021 IRC, R905.2.6, gives not less than four fasteners per strip shingle.

What the list counts

The starter strip runs along the eaves only, which is the assumption the list makes.
The cap counts the ridge and the hips.
Drip edge counts the eaves and the rakes, and each piece after the first loses the lap.
Waste goes on the total area once. Each item is then rounded up once, to a whole bundle, roll or piece.
Bundles are the area with waste divided by the area one bundle covers: the coverage per square the maker prints divided by the bundles per square the maker prints. The default shingle's sheet prints bundles per square and no coverage, so its square is the trade unit of one hundred square feet. The table below lists the figure for every shingle in the list.
Starter, cap and underlayment waste are none because no figure is sourced; add more yourself if your supplier says otherwise.

Underlayment is counted once or twice by pitch. The doubling is exact only for a roll 36 in^[5] wide with a side lap of 2 in^[5]; for other rolls follow the maker's instructions.

Area one bundle covers, by shingle

Bundles per square as each maker prints them, and the area one bundle covers, for each shingle in the calculator's list whose maker prints bundles per square, by maker

Bundles per square as each maker prints them, and the area one bundle covers, for each shingle in the calculator's list whose maker prints bundles per square, by maker
Shingle	Bundles per square	Area one bundle covers
CertainTeed Landmark	3 (per CertainTeed's data sheet, checked Nov 12, 2026)	32.8 ft²
CertainTeed Landmark Premium	4 (per CertainTeed's data sheet, checked Nov 12, 2026)	25 ft²
CertainTeed Landmark PRO	3 (per CertainTeed's data sheet, checked Nov 12, 2026)	33.333 ft²
GAF Camelot II	4 (per GAF's data sheet, checked Nov 12, 2026)	25 ft²
GAF Grand Sequoia	5 (per GAF's data sheet, checked Nov 12, 2026)	20 ft²
GAF Royal Sovereign	3 (per GAF's published data, checked Nov 12, 2026)	33.333 ft²
GAF Timberline HDZ	3 (per GAF's specification, checked Nov 12, 2026)	33.333 ft²
Malarkey Highlander AR	3 (per Malarkey's product page, checked Nov 12, 2026)	33.333 ft²
Malarkey Legacy Scotchgard	4 (per Malarkey's product page, checked Nov 12, 2026)	25 ft²
Malarkey Vista AR	3 (per Malarkey's product page, checked Nov 12, 2026)	33.333 ft²
Owens Corning Oakridge	3 (per Owens Corning's product page, checked Nov 12, 2026)	32.8 ft²
Owens Corning Supreme	3 (per Owens Corning's product page, checked Nov 12, 2026)	33.327 ft²
Owens Corning TruDefinition Duration	3 (per Owens Corning's product page, checked Nov 12, 2026)	32.8 ft²
Owens Corning TruDefinition Duration FLEX	3 (per Owens Corning's product page, checked Nov 12, 2026)	32.8 ft²
Owens Corning TruDefinition Duration STORM	3 (per Owens Corning's product page, checked Nov 12, 2026)	32.8 ft²
PABCO Cascade	approx. 5 (per PABCO's published data, checked Nov 12, 2026)	20 ft²
PABCO Paramount	approx. 5 (per PABCO's published data, checked Nov 12, 2026)	20 ft²
PABCO Premier	4 (per PABCO's data sheet, checked Nov 12, 2026)	25 ft²
PABCO Premier Radiance	approx. 4 (per PABCO's published data, checked Nov 12, 2026)	25 ft²
PABCO Prestige	approx. 4 (per PABCO's published data, checked Nov 12, 2026)	25 ft²

Sources: ^{[7][8][9][10][11][12][1][13][14][15][16][17][18][19][20][21][22]}

The shingles are listed by maker, then by name. The area one bundle covers is the coverage per square the maker prints divided by the bundles per square the maker prints, or one hundred square feet divided by the bundles per square where the sheet prints no coverage. The calculator divides the area with waste by this figure and rounds up once. Where a maker's printed coverage per square is under one hundred square feet, one hundred square feet of roof is more than one of that maker's squares. Shingles whose maker prints the coverage of one bundle instead are in the next table.

Coverage of one bundle where the maker prints it

Pieces per square and the coverage of one bundle as printed, for the shingles whose maker prints a coverage per bundle and no bundles per square

Pieces per square and the coverage of one bundle as printed, for the shingles whose maker prints a coverage per bundle and no bundles per square
Shingle	Pieces per square	Coverage of one bundle, as printed
IKO Cambridge	60	33 1/3 ft²
IKO Dynasty	60	33 1/3 ft²
IKO Marathon Plus AR	65	32.3 ft²
IKO Nordic	60	33 1/3 ft²

Figures in the Pieces per square and Coverage of one bundle, as printed columns are per IKO's product page, checked Nov 12, 2026.

Sources: ^{[23][24][25][26]}

These makers print how much one bundle covers and do not print bundles per square, so this site shows none for them. The bundle count divides the roof area by the printed coverage of one bundle and rounds up once.

Starter strip, by product

The length of starter strip one pack covers as each maker prints it, for each starter strip in the calculator's list, by maker

The length of starter strip one pack covers as each maker prints it, for each starter strip in the calculator's list, by maker
Starter strip	Length covered, as printed	Packs that cover it	Length one pack covers
Atlas Pro-Cut HP42 Starter	140 ft (per Atlas' data sheet, checked Nov 12, 2026)	1 bundle	140 ft
GAF Pro-Start	approx. 120.33 ft (per GAF's published data, checked Nov 12, 2026)	1 bundle	120 ft 3 15/16 in
IKO Leading Edge Plus	109 ft (per IKO's product page, checked Nov 12, 2026)	1 bundle	109 ft
Malarkey Smart Start	114 ft (per Malarkey's data sheet, checked Nov 12, 2026) 9 in (per Malarkey's data sheet, checked Nov 12, 2026)	1 bundle	114 ft 9 in
Owens Corning Starter Shingle Roll	33 ft (per Owens Corning's product page, checked Nov 12, 2026) 4 in (per Owens Corning's product page, checked Nov 12, 2026)	1 carton	33 ft 4 in
Owens Corning Starter Strip Plus	approx. 105 ft (per Owens Corning's product page, checked Nov 12, 2026)	1 bundle	105 ft
Owens Corning WoodStart	53.33 ft (per Owens Corning's product page, checked Nov 12, 2026)	1 bundle	53 ft 3 15/16 in
PABCO Universal Starter	73.33 ft (per PABCO's published data, checked Nov 12, 2026)	1 bundle	73 ft 3 15/16 in
TAMKO 10-Inch Starter	100 ft (per TAMKO's published data, checked Nov 12, 2026)	1 bundle	100 ft
TAMKO Perforated Starter	105 ft (per TAMKO's published data, checked Nov 12, 2026)	1 bundle	105 ft
TAMKO Shingle Starter	102 ft (per TAMKO's published data, checked Nov 12, 2026)	1 bundle	102 ft

Sources: ^{[27][2][28][29][30][31][32][21][33][34][35]}

The products are listed by maker, then by name. Each length is the maker's own printed figure for the pack it sells: a bundle, a box, a carton or a package. Where a maker prints a length for several bundles, the length one bundle covers is that length divided by the bundles. The calculator divides the length to cover by the length one pack covers and rounds up once.

Hip and ridge cap, by product

The length of hip and ridge one pack covers as each maker prints it, for each cap in the calculator's list, by maker

The length of hip and ridge one pack covers as each maker prints it, for each cap in the calculator's list, by maker
Hip and ridge cap	Length covered, as printed	Packs that cover it	Length one pack covers
Atlas Pro-Cut High Profile Hip & Ridge	20 ft (per Atlas' data sheet, checked Nov 12, 2026)	1 package	20 ft
Atlas Pro-Cut Hip & Ridge	31 ft (per Atlas' data sheet, checked Nov 12, 2026)	1 package	31 ft
CertainTeed Cedar Crest	20 ft (per CertainTeed's published data, checked Nov 12, 2026)	1 bundle	20 ft
CertainTeed Mountain Ridge	20 ft (per CertainTeed's data sheet, checked Nov 12, 2026)	1 box	20 ft
CertainTeed Shadow Ridge	30 ft (per CertainTeed's published data, checked Nov 12, 2026)	1 bundle	30 ft
CertainTeed Shangle Ridge	10 ft (per CertainTeed's data sheet, checked Nov 12, 2026)	1 box	10 ft
GAF Seal-A-Ridge	100 ft (per GAF's published data, checked Nov 12, 2026)	4 bundles (per GAF's published data, checked Nov 12, 2026)	25 ft
IKO Hip & Ridge 12	29.53 ft (per IKO's product page, checked Nov 12, 2026)	1 package	29 ft 6 3/8 in
Malarkey EZ-Ridge	20 ft (per Malarkey's product page, checked Nov 12, 2026)	1 box	20 ft
Malarkey RidgeFlex 10 in	41 ft (per Malarkey's product page, checked Nov 12, 2026) 3 in (per Malarkey's product page, checked Nov 12, 2026)	1 bundle	41 ft 3 in
Malarkey RidgeFlex 12 in	30 ft (per Malarkey's product page, checked Nov 12, 2026) 11 in (per Malarkey's product page, checked Nov 12, 2026)	1 bundle	30 ft 11 in
Owens Corning DuraRidge	20 ft (per Owens Corning's product page, checked Nov 12, 2026)	1 carton	20 ft
Owens Corning RIZERidge	33.3 ft (per Owens Corning's product page, checked Nov 12, 2026)	1 bundle	33 ft 3 5/8 in
PABCO Shadow Cap	41.25 ft (per PABCO's published data, checked Nov 12, 2026)	1 bundle	41 ft 3 in
PABCO Shadow Cap Wide	31.25 ft (per PABCO's published data, checked Nov 12, 2026)	1 bundle	31 ft 3 in
TAMKO 12-1/4 x 12 Hip & Ridge	100 ft (per TAMKO's published data, checked Nov 12, 2026)	3 bundles (per TAMKO's published data, checked Nov 12, 2026)	33 ft 4 in
TAMKO Heritage Designer Ridge	20 ft (per TAMKO's published data, checked Nov 12, 2026)	1 carton	20 ft

Sources: ^{[36][37][38][39][40][3][41][42][43][44][45][21][46][47]}

Underlayment rolls, by product

Roll width and length as each maker prints them, for each underlayment in the calculator's list, by maker

Sources: ^{[48][49][50][51][52][53][54][55][56][57][6][58][59]}

The rolls are listed by maker, then by name. Where the maker prints a coverage for the roll, the calculator uses it as printed; those rolls are in the coverage table. For every other roll it takes the printed width and length less the side lap and the end lap in the assumptions, which are inputs you can change, never another maker's figure.

Ice barrier rolls, by product

Roll width and length as each maker prints them, for each ice barrier roll in the calculator's list, by maker

Roll width and length as each maker prints them, for each ice barrier roll in the calculator's list, by maker
Ice barrier roll	Width, as printed	Length, as printed
CertainTeed WinterGuard	3 ft (per CertainTeed's data sheet, checked Nov 12, 2026)	65 ft (per CertainTeed's data sheet, checked Nov 12, 2026)
GAF WeatherWatch	36 in (per GAF's published data, checked Nov 12, 2026)	66.7 ft (per GAF's published data, checked Nov 12, 2026)
IKO GoldShield	3 ft (per IKO's product page, checked Nov 12, 2026)	66.7 ft (per IKO's product page, checked Nov 12, 2026)
IKO StormShield	36 in (per IKO's product page, checked Nov 12, 2026)	65 ft (per IKO's product page, checked Nov 12, 2026)
Malarkey Arctic Seal	36 in (per Malarkey's product page, checked Nov 12, 2026)	65 ft (per Malarkey's product page, checked Nov 12, 2026)
Owens Corning RhinoRoof Granulated	36 in (per Owens Corning's product page, checked Nov 12, 2026)	65 ft (per Owens Corning's product page, checked Nov 12, 2026)
Owens Corning Titanium PSU30	36 in (per Owens Corning's product page, checked Nov 12, 2026)	72 ft (per Owens Corning's product page, checked Nov 12, 2026)
Owens Corning WeatherLock Mat	3 ft (per Owens Corning's product page, checked Nov 12, 2026)	66.7 ft (per Owens Corning's product page, checked Nov 12, 2026)
TAMKO Moisture Guard	36 in (per TAMKO's published data, checked Nov 12, 2026)	64 ft (per TAMKO's published data, checked Nov 12, 2026) 6 in (per TAMKO's published data, checked Nov 12, 2026)

Sources: ^{[60][61][62][63][64][65][66][67][68]}

Coverage of one roll where the maker prints it

Coverage of one roll as printed, for the underlayment and ice barrier rolls whose maker prints one, by maker

Coverage of one roll as printed, for the underlayment and ice barrier rolls whose maker prints one, by maker
Roll	Coverage of one roll, as printed
CertainTeed RoofRunner	937.5 ft² (per CertainTeed's data sheet, checked Nov 12, 2026)
Owens Corning DeckDefense	937 ft² (per Owens Corning's product page, checked Nov 12, 2026)
Owens Corning ProArmor	929 ft² (per Owens Corning's product page, checked Nov 12, 2026)
TAMKO Moisture Guard	174.69 ft² (per TAMKO's published data, checked Nov 12, 2026)
TAMKO No. 15 felt	408 ft² (per TAMKO's published data, checked Nov 12, 2026)
TAMKO No. 30 felt	204 ft² (per TAMKO's published data, checked Nov 12, 2026)
TAMKO Synthetic Guard	905.67 ft² (per TAMKO's published data, checked Nov 12, 2026)

Sources: ^{[49][54][55][68][6][58]}

This is each maker's own figure for what one roll covers once it is lapped as the maker describes, shown as printed. The calculator divides the area to cover by it and rounds up once. Rolls not listed here print no coverage.

Why the total is rounded once

The example roof before waste: bundles from the total area, and bundles after rounding the squares up first

The example roof before waste: bundles from the total area, and bundles after rounding the squares up first
Method	Bundles
Total area first, rounded once at the bundle	41 bundles
Squares rounded up first	42 bundles

Rounding the squares up first can add a bundle that the total does not need, so the calculator rounds once, at the bundle.

Attic ventilation

The calculator's list does not include vent area. This section quotes the code's two figures, the base figure first and the exception figure beside the conditions the code quotes, and works them for an example attic floor.

The 2021 IRC, section R806.2, says “The minimum net free ventilating area shall be 1/150 of the area of the vented space.”^[69]
The 2021 IRC, section R806.2, says “The minimum net free ventilation area shall be 1/300 of the vented space provided both of the following conditions are met: 1. In Climate Zones 6, 7 and 8, a Class I or II vapor retarder is installed on the warm-in-winter side of the ceiling.”^[69]
The 2021 IRC, section R806.2, says “Not less than 40 percent and not more than 50 percent of the required ventilating area is provided by ventilators located in the upper portion of the attic or rafter space. Upper ventilators shall be located not more than 3 feet (914 mm) below the ridge…”^[69]
The 2021 IRC, section R806.2, says “Where the location of wall or roof framing members conflicts with the installation of upper ventilators, installation more than 3 feet (914 mm) below the ridge or highest point of the space shall be permitted.”^[69]

The code text does not settle how the climate-zone condition applies outside the zones it names. Building departments read it differently, and yours decides.

When the exception figure appears

The vent area for the example, the base figure first, then the exception figure and its upper-vent share, each with the denominator the code gives

The vent area for the example, the base figure first, then the exception figure and its upper-vent share, each with the denominator the code gives
Figure	Denominator in the code	Net free area for the example
Base figure, always first	150The 2021 IRC, section R806.2, says the minimum net free ventilating area is 1/150 of the area of the vented space.	1,152 in²
Exception figure, beside its conditions	300The 2021 IRC, section R806.2, exception: the net free ventilation area is 1/300 of the vented space provided both conditions are met, the first being a Class I or II vapor retarder in Climate Zones 6, 7 and 8.	576 in²
Upper vents, low end of the quoted share	40%The 2021 IRC, section R806.2, exception: the second condition is that not less than 40 percent and not more than 50 percent of the required ventilating area is provided by ventilators in the upper portion, not more than 3 feet below the ridge.	230.4 in²
Upper vents, high end of the quoted share	50%The 2021 IRC, section R806.2, exception: the second condition is that not less than 40 percent and not more than 50 percent of the required ventilating area is provided by ventilators in the upper portion, not more than 3 feet below the ridge.	288 in²

Source: ^[69]

The example's footprint stands in for an attic floor area. The exception figure and the upper-vent share show only beside the conditions quoted above.

What the code says about low slopes

For each value the code quotes, one row gives the value, where the code quotes it, and where the low-slope example sits: within, outside or at.

Asphalt shingles, lowest slope: 2 in 12, 2021 IRC, section R905.2.2. Example: at.
Double underlayment range: 2 in 12 to 4 in 12, 2021 IRC, section R905.2.2. Example: at.
Steeper slope, ice barrier distance: 8 in 12, 2021 IRC, section R905.1.2. Example: outside.

The 2021 IRC, section R905.2.2, says “Asphalt shingles shall be used only on roof slopes of 2 units vertical in 12 units horizontal (17-percent slope) or greater. For roof slopes from 2 units vertical in 12 units horizontal … up to 4 units vertical in 12 units horizontal (33-percent slope), double underlayment application is required…”^[5]
The 2021 IRC, Table R905.1.1(2), says “…underlayment shall be two layers applied in the following manner: apply a 19-inch strip of underlayment felt parallel to and starting at the eaves. … apply 36-inch-wide sheets of underlayment, overlapping successive sheets 19 inches. … End laps shall be 4 inches and shall be offset by 6 feet.”^[5]

Low slopes

A flat-topped shed roof at a low pitch: its area, the shingle bundles, and the underlayment with its layers doubled and the eave strip added

A flat-topped shed roof at a low pitch: its area, the shingle bundles, and the underlayment with its layers doubled and the eave strip added
Item	Result
Slope	2 in 12
Roof area	101.38 ft²
Shingles	4 bundles
Underlayment area with the layers doubled	202.76 ft²
Eave strip added before rounding	15.83 ft²
Eave strip width the table quotes	19 inTable R905.1.1(2) of the 2021 IRC, asphalt shingles with wind design not required, slopes from 2:12 up to 4:12: two layers, a 19 inch strip at the eaves, then 36 inch sheets lapped 19 inches; end laps 4 inches offset by 6 feet.
Coverage of one roll of the default felt, as printed	408 ft² (per TAMKO's published data, checked Nov 12, 2026)
Underlayment rolls of the default felt	1 roll

Sources: ^[5][6]

The strip width is the one the table quotes. The doubling is exact only for a roll as wide as the table's sheet with the table's side lap.

When an ice barrier applies

The code's own words below say where the ice barrier section applies. Your building department decides whether that describes your area, so the ice barrier is off in the main example.

The code gives its distance as a point inside the exterior wall line. When you switch the ice barrier on, the calculator measures from the eave edge to that point, your overhang plus the code's distance, then carries the band up the slope.

The 2021 IRC, section R905.1.2, says “…in areas where there has been a history of ice forming along the eaves … as designated in Table R301.2 … not less than 24 inches (610 mm) inside the exterior wall line … slope equal to or greater than 8 units vertical in 12 … not less than 36 inches (914 mm)…”^[5]

The 2021 IRC ice barrier distances

The distances the 2021 IRC gives for an ice barrier, inside the wall line and along the slope

The distances the 2021 IRC gives for an ice barrier, inside the wall line and along the slope
Item	2021 IRC value
Inside the exterior wall line	24 inThe 2021 IRC, section R905.1.2, says an ice barrier extends to a point not less than 24 inches inside the exterior wall line, and on slopes of 8 in 12 or more also not less than 36 inches along the slope from the eave edge.
On slopes this steep or steeper	8 in 12The 2021 IRC, section R905.1.2, says an ice barrier extends to a point not less than 24 inches inside the exterior wall line, and on slopes of 8 in 12 or more also not less than 36 inches along the slope from the eave edge.
Also along the slope from the eave edge	36 inThe 2021 IRC, section R905.1.2, says an ice barrier extends to a point not less than 24 inches inside the exterior wall line, and on slopes of 8 in 12 or more also not less than 36 inches along the slope from the eave edge.

Source: ^[5]

These are model-code values. The code your area has adopted may differ.

Ice barrier at the eaves

The ice barrier band up the slope for two eaves: a gentle pitch with an overhang, and the steeper pitch with none

The ice barrier band up the slope for two eaves: a gentle pitch with an overhang, and the steeper pitch with none
Case	Overhang	Code distance inside the wall line	Band up the slope
6/12, with an overhang	1 ft	24 inThe 2021 IRC, section R905.1.2, says an ice barrier extends to a point not less than 24 inches inside the exterior wall line, and on slopes of 8 in 12 or more also not less than 36 inches along the slope from the eave edge.	3 ft 4 1/4 in
8/12, with no overhang	0 in	24 inThe 2021 IRC, section R905.1.2, says an ice barrier extends to a point not less than 24 inches inside the exterior wall line, and on slopes of 8 in 12 or more also not less than 36 inches along the slope from the eave edge.	3 ft

Source: ^[5]

The band is the calculator's figure: from the eave edge to the code's point inside the exterior wall line, so your overhang plus the code's distance, carried up the slope. It is not the code's value.

6/12: your overhang and the code's distance inside the wall line govern.
8/12: the code's distance along the slope governs.

Common jobs

Roof area, squares, shingle bundles, cap bundles and underlayment layers for common jobs, each at its roof type's default waste

Roof area, squares, shingle bundles, cap bundles and underlayment layers for common jobs, each at its roof type's default waste
Job	Roof area	Squares with waste	Bundles	Cap bundles	Underlayment layers
Gable 40 ft by 30 ft, 6/12, with an overhang	1,502.64 ft²	16.53	50	2	1
Hip 40 ft by 30 ft, 6/12	1,341.64 ft²	15.43	47	4	1
Gable 36 ft 6 in by 24 ft 3 in, 4/12	933 ft²	10.26	31	2	1
Garage gable 24 ft by 24 ft, 4/12	607.16 ft²	6.68	21	1	1
House and garage together, 40 ft by 30 ft, 6/12 and 20 ft by 12 ft, 4/12	1,594.62 ft²	17.54	53	3	1

Areas are added before waste, so a house and its garage together take fewer bundles than the two bought separately.

Questions

How many bundles of shingles do I need?

Add the area of every roof plane first, add the waste allowance to that total, divide by the area one bundle covers and round up once. The calculator shows each step, so you can check the count against the bundles per square on your shingle's sheet.

What is a roofing square?

A square is the trade unit for a hundred square feet of roof. The calculator shows the roof area with waste in squares and counts bundles from the bundles per square the maker prints, and from the coverage per square where the maker prints one.

Why is waste its own line?

Waste is an allowance for cuts and mistakes, not a measured figure, and it is a common allowance rather than a sourced one. Keeping it on its own line lets you see the area before and after it, and change it if your roof has more cuts than usual.

Why are the starter and the cap counted separately?

Starter strip and ridge cap are sold in their own bundles and cover a length, not an area. The calculator counts the starter along the eaves and the cap along the ridge and the hips, each rounded up once to whole bundles.

How far up the roof does the ice barrier go?

The code wording is quoted on this page. The code gives its distance as a point inside the exterior wall line, so the calculator measures from the eave edge: your overhang plus the code's distance, carried up the slope. The ice barrier is off until you switch it on, and your building department decides whether it applies to your area.

What is the attic ventilation rule?

The code gives a base ratio of vent area to the vented space, and the lower ratio in the exception only when its quoted conditions are met. This page works the figures for an example attic, base figure first and the exception figure only beside those conditions; the calculator's list does not include vent area. Your building department decides how the conditions apply to your attic.

Does the calculator give a cost?

No. It gives quantities. Multiply each quantity by the price from your own supplier, since prices differ by shingle, region and season.

Estimates for planning, not professional advice. This page is provided as is. Its figures are estimates worked out from what you enter and from published product data. It is not engineering, architectural, building-code, legal or contractor advice. Products and local codes vary, so check product labels, your supplier and your local building department. For structural work, consult a licensed professional.

HoneyDoMath is software from The Stroop LLC. It is not an engineering firm, architect, contractor, building department or retailer, it is not a substitute for a licensed professional, and nothing on this page creates a professional relationship with you. The full disclaimer and limits of liability are in the Terms of Use. By using this page, you agree to those terms. See something wrong? Report an error.

Local codes and amendments differ; your building department decides.

Sources (69)

Timberline HDZ Shingles Specification Sheet (opens in new tab), GAF, RESGN467HDZ-0526, 2026. Manufacturer data.
“Bundles/Square: 3 Pieces/Square: 64”
Per GAF's specification, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 1)
Pro-Start Starter Strip Shingles Sell Sheet (opens in new tab), GAF, RESGN546-0325, 2025. Manufacturer data.
“Approx. 120.33 lineal feet (36.69 lm) (when split in half)”
Per GAF's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 2)
Seal-A-Ridge Ridge Cap Shingles Sell Sheet (opens in new tab), GAF, RESHR112-1124, 2024. Manufacturer data.
“4 bundles cover 100 linear feet (30 lm)”
Per GAF's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 3)
Drip Edge System info sheet (opens in new tab), Englert Inc., undated. Manufacturer data.
“Englert Drip Edge is available in 6” and 4” sizes and comes in 10’ lengths.”
Per Englert's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 4)
2021 IRC, Chapter 9 Roof Assemblies, R905.2.8.5 Drip edge (opens in new tab), International Code Council, 2021 IRC. Code or government.
“…Adjacent segments of drip edge shall be overlapped not less than 2 inches (51 mm). … mechanically fastened to the roof deck at not more than 12 inches (305 mm)…”

“…not less than four fasteners per strip shingle or two fasteners per individual shingle.”
“…underlayment shall be two layers applied in the following manner: apply a 19-inch strip of underlayment felt parallel to and starting at the eaves. … apply 36-inch-wide sheets of underlayment, overlapping successive sheets 19 inches. … End laps shall be 4 inches and shall be offset by 6 feet.”
“…underlayment shall be one layer applied in the following manner: underlayment shall be applied shingle fashion, parallel to and starting from the eave and lapped 2 inches, … End laps shall be 4 inches and shall be offset by 6 feet.”
“Asphalt shingles shall be used only on roof slopes of 2 units vertical in 12 units horizontal (17-percent slope) or greater. For roof slopes from 2 units vertical in 12 units horizontal … up to 4 units vertical in 12 units horizontal (33-percent slope), double underlayment application is required…”
“…in areas where there has been a history of ice forming along the eaves … as designated in Table R301.2 … not less than 24 inches (610 mm) inside the exterior wall line … slope equal to or greater than 8 units vertical in 12 … not less than 36 inches (914 mm)…”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 5)
TAMKO Underlayments Brochure (opens in new tab), TAMKO Building Products LLC, brochure, copyright 2020 TAMKO Building Products LLC. Manufacturer data.
“No. 15 Asphalt Saturated Organic Felt 36" … 144' 408 sq. ft.”

“No. 30 Asphalt Saturated Organic Felt 36" … 72' 204 sq. ft.”
Per TAMKO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 6)
Technical Data Sheet, Landmark Shingles (opens in new tab), CertainTeed LLC, Landmark_TDS_CTRCOMM-015_2408_E, 08/24. Manufacturer data.
“Shingles per square 65 Bundles per square 3 Approximate Coverage per square 98.4 square feet”
Per CertainTeed's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 7)
Technical Data Sheet, Landmark Premium Shingles (opens in new tab), CertainTeed LLC, LandmarkPremium-TDS-CTRCOMM-015-2508-E, 08/25. Manufacturer data.
“Shingles/Square (approx.) 66 Bundles per square 4 Coverage per square 100 square feet”
Per CertainTeed's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 8)
Technical Data Sheet, Landmark PRO Shingles (opens in new tab), CertainTeed LLC, LandmarkPro_TDS_CTRCOMM-015_2310_E, 10/23. Manufacturer data.
“Shingles/Square (approx.) 66 Bundles per square 3 Coverage per square 100 square feet”
Per CertainTeed's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 9)
Camelot II Shingles Data Sheet (opens in new tab), GAF, RESGN467CII-0426, 2026. Manufacturer data.
“Bundles/Square: 4 Pieces/Square: 56”
Per GAF's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 10)
Grand Sequoia Shingles Data Sheet (opens in new tab), GAF, RESGN467GS-0426, 2026. Manufacturer data.
“Bundles/Square: 5 Pieces/Square: 72”
Per GAF's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 11)
Royal Sovereign Shingles (metric) Product Information Sheet (opens in new tab), GAF, undated. Manufacturer data.
“Bundles/Square: 3 Pieces/Square: 64 Nails/Square: 256 (384 where 6 nails per shingle is required)”
Per GAF's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 12)
Highlander AR shingles, technical specs (opens in new tab), Malarkey Roofing Products, product page. Manufacturer data.
“Bundles/SQ: 3 Shingles/SQ: 66 … Highlander® AR shingles are packaged to deliver a full square, with 3 bundles equaling 100 square feet of roof coverage.”
Per Malarkey's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 13)
Legacy Scotchgard shingles, technical specs (opens in new tab), Malarkey Roofing Products, product page. Manufacturer data.
“Bundles/SQ: 4 Shingles/SQ: 64 … Legacy® Scotchgard™ shingles are packaged to deliver a full square, with 4 bundles equaling 100 square feet of roof coverage.”
Per Malarkey's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 14)
Vista AR shingles, technical specs (opens in new tab), Malarkey Roofing Products, product page. Manufacturer data.
“Bundles/SQ: 3 Shingles/SQ: 66 … Vista® AR shingles are packaged to deliver a full square, with 3 bundles equaling 100 square feet of roof coverage.”
Per Malarkey's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 15)
Oakridge Shingles, Technical Characteristics (nominal values) (opens in new tab), Owens Corning, product page. Manufacturer data.
“Nominal Size 13 1/4" x 39 3/8" Exposure 5 5/8" Shingles Per Square 64 Bundles Per Square 3 Coverage Per Square 98.4 sq. ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 16)
Supreme 3 Tab Shingles, Technical Characteristics (nominal values) (opens in new tab), Owens Corning, product page. Manufacturer data.
“Shingles Per Square 65 Bundles Per Square 3 Coverage Per Square 99.98 sq. ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 17)
TruDefinition Duration Shingles, Technical Characteristics (nominal values) (opens in new tab), Owens Corning, product page. Manufacturer data.
“Shingles Per Square 64 Bundles Per Square 3 Coverage Per Square 98.4 sq. ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 18)
TruDefinition Duration FLEX Shingles, Technical Characteristics (nominal values) (opens in new tab), Owens Corning, product page. Manufacturer data.
“Nominal Size 13 1/4" x 39 3/8" Exposure 5 5/8" Shingles Per Square 64 Bundles Per Square 3 Coverage Per Square 98.4 sq. ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 19)
TruDefinition Duration STORM Shingles, Technical Characteristics (nominal values) (opens in new tab), Owens Corning, product page. Manufacturer data.
“Nominal Size 13 1/4" x 39 3/8" Exposure 5 5/8" Shingles Per Square 64 Bundles Per Square 3 Coverage Per Square 98.4 sq. ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 20)
Product Guide (opens in new tab), PABCO Roofing Products, Revised 1-29-2025. Manufacturer data.
“APPROX BUNDLES PER SQUARE APPROX SHINGLES PER SQUARE … CASCADE™ … 15-1/2” x 40” 4-1/2” 5 80 349 lbs”

“APPROX BUNDLES PER SQUARE APPROX SHINGLES PER SQUARE … PARAMOUNT® … 15-1/2” x 40” 4-1/2” 5 80 349 lbs”
“APPROX BUNDLES PER SQUARE APPROX SHINGLES PER SQUARE … PREMIER RADIANCE® … 13-1/4” x 40” 5-5/8” 4 64 233 lbs”
“APPROX BUNDLES PER SQUARE APPROX SHINGLES PER SQUARE … PABCO PRESTIGE® … 13-1/4” x 40” 5-5/8” 4 64 287 lbs”
“COVERAGE (LINEAR FEET) SHINGLES PER BUNDLE … UNIVERSAL STARTER™ For Use With All Shingles 13-1/4” x 40” N/A 73.33 22”
“COVERAGE (LINEAR FEET) SHINGLES PER BUNDLE … SHADOW CAP™ For Use on Hips & Ridges With All Shingles 13-1/4” x 39-3/8” 5-5/8” 41.25 22”
“COVERAGE (LINEAR FEET) SHINGLES PER BUNDLE … SHADOW CAP WIDE™ For Use on Hips & Ridges With All Shingles 13-1/4” x 39-3/8” 5-5/8” 31.25 22”
Per PABCO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 21)
PABCO Premier Technical Data Sheet (opens in new tab), PABCO Roofing Products, Rev 04/17/25. Manufacturer data.
“Weather Exposure 5 5/8” Offset 5 5/8” Shingles per square 64 Bundles per square 4 Bundles per pallet 68”
Per PABCO's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 22)
Cambridge shingles, product specifications (opens in new tab), IKO, product page. Manufacturer data.
“Dimensions (LxW) 40 7/8 inches x 13 3/4 inches (1,038 mm x 349 mm) Exposure 5 7/8 inches (149 mm) Coverage per Bundle 33 1/3 sq. ft. (3.1 sq.m) Bundles per Pallet 60 Shingles per Square 60 Shingles per Bundle 20”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 23)
Dynasty shingles, product specifications (opens in new tab), IKO, product page. Manufacturer data.
“Dimensions (LxW) 40 7/8 inches x 13 3/4 inches (1,038 mm x 349 mm) Exposure 5 7/8 inches (149 mm) Coverage per Bundle 33 1/3 sq. ft. (3.1 sq. m) Bundles per Pallet 60 Shingles per Square 60 Shingles per Bundle 20”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 24)
Marathon Plus AR shingles, specifications (opens in new tab), IKO, product page. Manufacturer data.
“Size 39 3/8" x 13 1/4" (1000 mm x 336 mm) Exposure 5 5/8" (143 mm) Coverage Per Package 32.3 sq. ft. (3.0 m²) Qty Per Pallet 60 bundles Shingles Per Square 65 Quantity Per Unit/Package 21 shingles”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 25)
Nordic shingles, product specifications (opens in new tab), IKO, product page. Manufacturer data.
“Dimensions (LxW) 40 7/8 inches x 13 3/4 inches (1,038 mm x 349 mm) Exposure 5 7/8 inches (149 mm) Coverage per Bundle 33 1/3 sq. ft. (3.1 sq.m) Bundles per Pallet 56 Shingles per Square 60 Shingles per Bundle 20”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 26)
Pro-Cut HP42 Starter Shingles Product Data Sheet (opens in new tab), Atlas Roofing Corporation, ATL-267586-00 10/26. Manufacturer data.
“Pro-Cut® HP42® starter is packaged 20 shingles per bundle (40 starter shingles), 140 lineal feet.”
Per Atlas' data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 27)
Leading Edge Plus roof starter, product specifications (opens in new tab), IKO, product page. Manufacturer data.
“Starter Strips per Bundle 32 (2 pieces per shingle) Coverage per Bundle 109 linear ft. (33 linear m) Bundles per Pallet 54 Shingles per Bundle 16”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 28)
Technical Product Data Sheet, 210 Smart Start (opens in new tab), Malarkey Roofing Products, Effective 05/23. Manufacturer data.
“LINEAR FT./BUNDLE 114' 9" 35 m … SHINGLES/BUNDLE 18 full-size 36 pieces”
Per Malarkey's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 29)
Starter Shingle Roll, technical information (opens in new tab), Owens Corning, product page. Manufacturer data.
“Roll Size 7.2" wide x 33' 4" long (0.183m x 10.18m) Pieces per Carton 1 Lineal Feet per Carton 33'4"”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 30)
Starter Strip Plus Shingle, technical information (opens in new tab), Owens Corning, product page. Manufacturer data.
“Shingles per Bundle 16 Pieces per Bundle 32 (7-3/4 " x 39-3/8" [197 mm x 1000 mm]) Lineal Feet per Bundle Approximately 105 (32.004 m)”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 31)
WoodStart Starter Strip Shingle, technical information (opens in new tab), Owens Corning, product page. Manufacturer data.
“Size 40” x 13 ³/8” Pieces per Bundle 16 Lineal Feet per Bundle 53.33”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 32)
TAMKO 10-Inch Starter, Starter Course Shingles Product Data (opens in new tab), TAMKO Building Products LLC, Rev. 10/01/2021. Manufacturer data.
“Shingle Size 10" × 40" Shingles per Bundle 30 Coverage per Bundle (linear feet) 100 ft.”
Per TAMKO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 33)
TAMKO Perforated Starter, Starter Course Shingles Product Data (opens in new tab), TAMKO Building Products LLC, Rev. 10/01/2021. Manufacturer data.
“One bundle contains 16 perforated shingles to be separated into 32 starter strip shingles Coverage per bundle 105 linear ft per bundle”
Per TAMKO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 34)
TAMKO Shingle Starter, Starter Course Shingles Product Data (opens in new tab), TAMKO Building Products LLC, Rev. 10/01/2021. Manufacturer data.
“Shingle size 7" × 36" Shingles per bundle 34 Coverage per bundle (lineal ft) 102 ft.”
Per TAMKO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 35)
Pro-Cut High Profile Hip & Ridge Product Data Sheet (opens in new tab), Atlas Roofing Corporation, ATL-246773-00 1/24. Manufacturer data.
“Dimensions 10" x 11½" Exposure 8¼" Coverage 20 Linear Feet Shingles Per Package 30”
Per Atlas' data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 36)
Pro-Cut Hip & Ridge Product Data Sheet (opens in new tab), Atlas Roofing Corporation, ATL-267503-01 06/26. Manufacturer data.
“Dimensions: 12" x 12" Exposure: 5-5/8" Coverage: 31 Linear Feet Hip & Ridge Shingles per Package: 66”
Per Atlas' data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 37)
Roofing Selection Guide (opens in new tab), CertainTeed LLC, Code No. 00-00-253-US-EN, 06/26. Manufacturer data.
“Hip and ridge for Landmark Series, Presidential Shake, Presidential Shake TL, Highland Slate and Belmont; 20 lineal ft. per bundle”

“Shadow Ridge … Hip and ridge for Presidential TL, Presidential and Landmark Series; 30 lineal ft. per bundle; 24 shingles per bundle”
Per CertainTeed's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 38)
Technical Data Sheet, Mountain Ridge Shingles (Hip and Ridge Accessory) (opens in new tab), CertainTeed LLC, MountainRidge_TDS_CTRCOMM-015_2203_E, 03/22. Manufacturer data.
“Pieces/Box: 30 Weather Exposure: 8" Coverage/Box (Lineal Ft.) 20”
Per CertainTeed's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 39)
Technical Data Sheet, Shangle Ridge Hip and Ridge Accessory (opens in new tab), CertainTeed LLC, ShangleRidge_TDS_CTRCOMM-015_1026_E, 10/26. Manufacturer data.
“Pieces/Box: 15 Weather Exposure: 8" Coverage/Box (Lineal Ft.) 10”
Per CertainTeed's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 40)
Hip and Ridge Cap Shingles, specifications (opens in new tab), IKO, product page. Manufacturer data.
“Size 914 mm x 337 mm (36" x 13 1/4") Coverage Per Package 9 linear m (29.53 linear ft) Qty Per Pallet 64 Quantity Per Unit/Package 21 x 3 = 63”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 41)
EZ-Ridge shingles, technical specs (opens in new tab), Malarkey Roofing Products, product page. Manufacturer data.
“8″ Model Length: 11-1/2″ Width: 8″ Exposure: 8-1/4″ Linear Coverage: 20′ … Shingles/Box: 30”
Per Malarkey's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 42)
RidgeFlex, technical specs (opens in new tab), Malarkey Roofing Products, product page. Manufacturer data.
“10″ Model: Length: 39-1/2″ Width: 13-1/4″ Exposure: 5-5/8″ Linear Coverage: 41′ 3″ … SKU: 225 Shingles/Bundle: 22 Units/Bundle: 88”

“12″ Model: Length: 36″ Width: 13-1/4″ Exposure: 5-5/8″ Linear Coverage: 30′ 11″ … SKU: 227 Shingles/Bundle: 22 Units/Bundle: 66”
Per Malarkey's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 43)
DuraRidge Hip & Ridge Shingles, technical information (opens in new tab), Owens Corning, product page. Manufacturer data.
“Nominal Size 12" x 10 5/8" Exposure 8" Pieces per Carton 30 Lineal Feet per Carton 20ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 44)
RIZERidge Hip & Ridge Shingles, technical information (opens in new tab), Owens Corning, product page. Manufacturer data.
“Exposure 6" Shingles per Bundle 22 Pieces per Shingle/Bundle 3/66 Lineal Feet per Bundle 33.3ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 45)
TAMKO 12-1/4 x 12 Hip & Ridge, Roofing Accessory Product Data (opens in new tab), TAMKO Building Products LLC, Rev. 04/28/2023. Manufacturer data.
“Exposure 5-1/8" Perforated Shingles per 100 lineal feet 234 Bundles per 100 lineal feet 3”
Per TAMKO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 46)
Heritage Designer Ridge, High Profile Ridge Product Data (opens in new tab), TAMKO Building Products LLC, Rev. 07/31/2019. Manufacturer data.
“Exposure 8" Linear ft. per carton 20 Shingles per 100 linear ft. 150 Shingles per carton 30”
Per TAMKO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 47)
Technical Data Sheet, DiamondDeck High Performance Synthetic Underlayment (opens in new tab), CertainTeed LLC, DiamondDeck-TDS-CTRCOMM-015-2608-E, 08/26. Manufacturer data.
“Roll Area 1000 ft2 Roll Length 250 ft Roll Width 4 ft”
Per CertainTeed's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 48)
RoofRunner Technical Data Sheet (opens in new tab), CertainTeed LLC, Updated 03/2019. Manufacturer data.
“Roll Length (ft.): 250 Roll Width (ft.): 4 … Roll Size (Gross sq. ft.): 1000 Roll Coverage (Typical net sq. ft.): 937.5”
Per CertainTeed's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 49)
FeltBuster Synthetic Roofing Felt Sell Sheet (opens in new tab), GAF, RESUL183-0125, 2025. Manufacturer data.
“Roll size: 10 squares (1,000 sq. ft. … (excludes laps) Roll width: 48" (1.22 m) Roll length: 250' (76.2 m)”
Per GAF's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 50)
Stormtite Synthetic Underlayment, specifications (opens in new tab), IKO, product page. Manufacturer data.
“Size 76.2 m x 1,219 mm (250' x 48") Area 92.9 m² (1000 sq. ft.)”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 51)
Secure Start Lite, technical specs (opens in new tab), Malarkey Roofing Products, product page. Manufacturer data.
“SKU: 1029 L: 250′ W: 48″ SQ/Roll: 10”
Per Malarkey's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 52)
Secure Start Plus, technical specs (opens in new tab), Malarkey Roofing Products, product page. Manufacturer data.
“SKU: 1031 L: 250′ W: 48″ SQ/Roll: 10”
Per Malarkey's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 53)
DeckDefense High Performance Synthetic Roof Underlayment, product information (opens in new tab), Owens Corning, product page. Manufacturer data.
“Roll Size 10 sq. Length 250 ft. Width 48 in. Weight 36 lb. … Coverage (with 3-in. overlap) 937 sq. ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 54)
ProArmor Synthetic Roof Underlayment, product information (opens in new tab), Owens Corning, product page. Manufacturer data.
“Length 286 ft. Width 42 in. … Coverage (with 3-in. overlap) 929 sq. ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 55)
RhinoRoof U20 Synthetic Roofing Underlayment, specifications (opens in new tab), Owens Corning, product page. Manufacturer data.
“Length per roll: 286’ / 87 m Width per roll: 42” / 1.1 m … Roll size: 10 sq / 93 m²”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 56)
Titanium UDL30 Synthetic Roofing Underlayment, roll specs (opens in new tab), Owens Corning, product page. Manufacturer data.
“LENGTH PER ROLL 250’ / 76.2 M WIDTH PER ROLL 48” / 122 CM WEIGHT PER ROLL 40 LBS / 18.2 KG ROLL SIZE 10 SQ”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 57)
Synthetic Guard, Synthetic Underlayment Product Data (opens in new tab), TAMKO Building Products LLC, Rev. 03/14/2025. Manufacturer data.
“Roll Dimensions 42" × 286' Roll Coverage 905.67 sq. ft. (± 12.44 sq. ft.) Roll Contains 1001 sq. ft. (± 12.49 sq. ft.)”
Per TAMKO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 58)
ASTM Roofing Felts (opens in new tab), Tarco, product page. Manufacturer data.
“15# ASTM Specification Felt Meets ASTM D226, Type I Dimensions- 144' X 36" Coverage per Roll- 4 Squares Approx. Sq. Ft. per Roll- 432 Sq. Ft.”

“30# ASTM Specification Felt Meets ASTM D226, Type II Dimensions- 72' X 36" Coverage per Roll- 2 Squares Approx. Sq. Ft. per Roll- 216 Sq. Ft.”
Per Tarco's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 59)
WinterGuard Granular, Sand & Sand X Waterproofing Shingle Underlayment Technical Data Sheet (opens in new tab), CertainTeed LLC, CTRCOMM-015-2405-E, 05/24. Manufacturer data.
“Sand (short) Sand Granular Sand X Roll Area (sq.ft.) 97.5 195 195 195 Roll Length (ft.) 32.5 65 65 65 Roll Width (ft.) 3 3 3 3 … Side Laps (in.) 6 6 4 3 End Laps (in.) 6 6 6 6”
Per CertainTeed's data sheet, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 60)
WeatherWatch Mineral-Surfaced Leak Barrier Sell Sheet (opens in new tab), GAF, RESUL103-0325, 2025. Manufacturer data.
“200 ft.2 (18.58 sq. m) per roll (excludes laps) Roll width: 36" (.914 m) Roll length: 66.7' (20.33 m)”
Per GAF's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 61)
GoldShield Premium Ice and Water Protector, specifications (opens in new tab), IKO, product page. Manufacturer data.
“Size 20.32 m x 0.91 m (66.7' x 3') Area 18.6 m² (200 sq. ft.)”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 62)
StormShield Ice and Water Protector, specifications (opens in new tab), IKO, product page. Manufacturer data.
“Size 19.8 m x 914 mm (65' x 36") Area 18.1 m² (195 sq. ft.)”
Per IKO's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 63)
Arctic Seal, technical specs (opens in new tab), Malarkey Roofing Products, product page. Manufacturer data.
“SKU: 401 L: 65′ W: 36″ SQ/Roll: 2”
Per Malarkey's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 64)
RhinoRoof Granulated Self-Adhered Underlayment, specifications (opens in new tab), Owens Corning, product page. Manufacturer data.
“Roll size: 1.95 sq (18 m²) … Length per roll: 65ft (19.8 m) … Width per roll: 36 in (91 cm)”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 65)
Titanium PSU30 High-Temp Self-Adhered Underlayment, roll specs (opens in new tab), Owens Corning, product page. Manufacturer data.
“LENGTH PER ROLL 72’ / 22 M WIDTH PER ROLL 36” / 91.4 CM WEIGHT PER ROLL 48 LBS / 21.8 KG ROLL SIZE 2.16 SQ / 20 M²”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 66)
WeatherLock Mat Self-Sealing Waterproofing Barrier, typical values (opens in new tab), Owens Corning, product page. Manufacturer data.
“2 sq. roll Length 66.7 ft. (21.3 m.) Width 3 ft (0.9 m.) Gross Coverage 200 sq. ft.”
Per Owens Corning's product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 67)
Moisture Guard, Ice & Rain Underlayment Product Data (opens in new tab), TAMKO Building Products LLC, Rev. 08/13/2021. Manufacturer data.
“1.74 Sales Square Roll … 36" × 64'6" … 174.69 sq. ft. (±1.52 sq. ft.) … 193.5 sq. ft. (±1.68 sq. ft.)”
Per TAMKO's published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 68)
2021 IRC, Chapter 8 Roof-Ceiling Construction, R806.2 Minimum vent area (opens in new tab), International Code Council, 2021 IRC. Code or government.
“The minimum net free ventilating area shall be 1/150 of the area of the vented space.”

“The minimum net free ventilation area shall be 1/300 of the vented space provided both of the following conditions are met: 1. In Climate Zones 6, 7 and 8, a Class I or II vapor retarder is installed on the warm-in-winter side of the ceiling.”
“Not less than 40 percent and not more than 50 percent of the required ventilating area is provided by ventilators located in the upper portion of the attic or rafter space. Upper ventilators shall be located not more than 3 feet (914 mm) below the ridge…”
“Where the location of wall or roof framing members conflicts with the installation of upper ventilators, installation more than 3 feet (914 mm) below the ridge or highest point of the space shall be permitted.”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 69)

These are summaries of what the sources say, not professional advice. Codes and product data change. Check with your building department and the product label about your own project.

Sources

[1] GAF, Timberline HDZ Shingles Specification Sheet. Checked November 12, 2026. https://www.gaf.com/en-us/document-library/documents/specifications/timberline-hdz-shingles-spec-sheet-resgn467hdz.pdf
[2] GAF, Pro-Start Starter Strip Shingles Sell Sheet. Checked November 12, 2026. https://www.gaf.com/en-us/document-library/documents/data-sheets/pro-start-starter-strip-shingles-sell-sheet-resgn546.pdf
[3] GAF, Seal-A-Ridge Ridge Cap Shingles Sell Sheet. Checked November 12, 2026. https://www.gaf.com/en-us/document-library/documents/data-sheets/seal-a-ridge-ridge-cap-shingles-sell-sheet-reshr112.pdf
[4] Englert, Drip Edge System info sheet. Checked November 12, 2026. https://www.englertinc.com/sites/default/files/drip-edge-info-sheet.pdf
[5] International Code Council, 2021 IRC, Chapter 9 Roof Assemblies, R905.2.8.5 Drip edge. Checked November 12, 2026. https://codes.iccsafe.org/content/IRC2021P2/chapter-9-roof-assemblies
[6] TAMKO, TAMKO Underlayments Brochure. Checked November 12, 2026. https://tamko.com/docs/brochures/TAMKO-Underlayments-Brochure
[7] CertainTeed, Technical Data Sheet, Landmark Shingles. Checked November 12, 2026. https://certainteed.widen.net/content/xnk5hrkbzv/pdf/Landmark_TDS_CTRCOMM-015_2408_E.pdf
[8] CertainTeed, Technical Data Sheet, Landmark Premium Shingles. Checked November 12, 2026. https://certainteed.widen.net/content/daknr9xdxg/pdf/LandmarkPremium-TDS-CTRCOMM-015-2508-E.pdf
[9] CertainTeed, Technical Data Sheet, Landmark PRO Shingles. Checked November 12, 2026. https://certainteed.widen.net/content/7swc1einv3/pdf/LandmarkPro_TDS_CTRCOMM-015_2310_E.pdf
[10] GAF, Camelot II Shingles Data Sheet. Checked November 12, 2026. https://www.gaf.com/en-us/document-library/documents/data-sheets/camelot-ii-shingles-data-sheet-resgn467cii.pdf
[11] GAF, Grand Sequoia Shingles Data Sheet. Checked November 12, 2026. https://www.gaf.com/en-us/document-library/documents/data-sheets/grand-sequoia-shingles-data-sheet-resgn467gs.pdf
[12] GAF, Royal Sovereign Shingles (metric) Product Information Sheet. Checked November 12, 2026. https://www.gaf.com/en-us/document-library/documents/data-sheets/royal-sovereign-metrics-_data-sheet.pdf
[13] Malarkey, Highlander AR shingles, technical specs. Checked November 12, 2026. https://www.malarkeyroofing.com/products/shingles-overview/highlander-ar-shingles/
[14] Malarkey, Legacy Scotchgard shingles, technical specs. Checked November 12, 2026. https://www.malarkeyroofing.com/products/shingles-overview/legacy-scotchgard-shingles/
[15] Malarkey, Vista AR shingles, technical specs. Checked November 12, 2026. https://www.malarkeyroofing.com/products/shingles-overview/vista-ar-shingles/
[16] Owens Corning, Oakridge Shingles, Technical Characteristics (nominal values). Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/shingles/oakridge
[17] Owens Corning, Supreme 3 Tab Shingles, Technical Characteristics (nominal values). Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/shingles/supreme
[18] Owens Corning, TruDefinition Duration Shingles, Technical Characteristics (nominal values). Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/shingles/trudefinition-duration
[19] Owens Corning, TruDefinition Duration FLEX Shingles, Technical Characteristics (nominal values). Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/shingles/trudefinition-duration-flex
[20] Owens Corning, TruDefinition Duration STORM Shingles, Technical Characteristics (nominal values). Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/shingles/trudefinition-duration-storm
[21] PABCO, Product Guide. Checked November 12, 2026. https://pabcoroofing.com/wp-content/uploads/2025/01/2025-Product-Guide-Final-1-29-25.pdf
[22] PABCO, PABCO Premier Technical Data Sheet. Checked November 12, 2026. https://pabcoroofing.com/wp-content/uploads/2025/04/PABCO-Premier-TDS-4-21-25.pdf
[23] IKO, Cambridge shingles, product specifications. Checked November 12, 2026. https://www.iko.com/na/product/cambridge/
[24] IKO, Dynasty shingles, product specifications. Checked November 12, 2026. https://www.iko.com/na/product/dynasty/
[25] IKO, Marathon Plus AR shingles, specifications. Checked November 12, 2026. https://www.iko.com/na/product/marathon-plus-ar-traditional-3-tab-shingles/
[26] IKO, Nordic shingles, product specifications. Checked November 12, 2026. https://www.iko.com/na/product/nordic/
[27] Atlas, Pro-Cut HP42 Starter Shingles Product Data Sheet. Checked November 12, 2026. https://www.atlasroofing.com/img/Literature/Pro-Cut-HP42-Starter-Shingles-Data-Sheet_2026-10-07-223429_cfwg.pdf
[28] IKO, Leading Edge Plus roof starter, product specifications. Checked November 12, 2026. https://www.iko.com/na/product/leading-edge-plus-roof-starter/
[29] Malarkey, Technical Product Data Sheet, 210 Smart Start. Checked November 12, 2026. https://www.malarkeyroofing.com/app/uploads/2021/04/210-smart-start-tech-data-sheet-malarkey.pdf
[30] Owens Corning, Starter Shingle Roll, technical information. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/starter-roll
[31] Owens Corning, Starter Strip Plus Shingle, technical information. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/starter-strip-plus
[32] Owens Corning, WoodStart Starter Strip Shingle, technical information. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/woodstart-starter-shingle
[33] TAMKO, TAMKO 10-Inch Starter, Starter Course Shingles Product Data. Checked November 12, 2026. https://www.tamko.com/docs/default-source/data-sheets/tamko-10-inch-starter-data-sheet.pdf
[34] TAMKO, TAMKO Perforated Starter, Starter Course Shingles Product Data. Checked November 12, 2026. https://www.tamko.com/docs/default-source/data-sheets/tamko-perforated-starter-data-sheet.pdf
[35] TAMKO, TAMKO Shingle Starter, Starter Course Shingles Product Data. Checked November 12, 2026. https://www.tamko.com/docs/default-source/data-sheets/tamko-shingle-starter-data-sheet.pdf
[36] Atlas, Pro-Cut High Profile Hip & Ridge Product Data Sheet. Checked November 12, 2026. https://www.atlasroofing.com/img/product-resources/Pro-Cut-High-Profile-Hip-Ridge-Data-Sheet.pdf
[37] Atlas, Pro-Cut Hip & Ridge Product Data Sheet. Checked November 12, 2026. https://www.atlasroofing.com/img/Literature/Pro-Cut-Hip-Ridge-Data-Sheet.pdf
[38] CertainTeed, Roofing Selection Guide. Checked November 12, 2026. https://certainteed.widen.net/content/4wi6bh5vlh/pdf/roofing-selection-guide-00-00-253-US-EN-2606.pdf
[39] CertainTeed, Technical Data Sheet, Mountain Ridge Shingles (Hip and Ridge Accessory). Checked November 12, 2026. https://certainteed.widen.net/content/chfnyd8h3l/pdf/MountainRidge_TDS_CTRCOMM-015_2203_E.pdf
[40] CertainTeed, Technical Data Sheet, Shangle Ridge Hip and Ridge Accessory. Checked November 12, 2026. https://certainteed.widen.net/content/fc3pixoru8/pdf/ShangleRidge_TDS_CTRCOMM-015_1026_E.pdf
[41] IKO, Hip and Ridge Cap Shingles, specifications. Checked November 12, 2026. https://www.iko.com/na/product/hip-and-ridge-cap-shingles/
[42] Malarkey, EZ-Ridge shingles, technical specs. Checked November 12, 2026. https://www.malarkeyroofing.com/products/accessories/ez-ridge-shingles/
[43] Malarkey, RidgeFlex, technical specs. Checked November 12, 2026. https://www.malarkeyroofing.com/products/accessories/ridge-flex/
[44] Owens Corning, DuraRidge Hip & Ridge Shingles, technical information. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/duraridge-hip-ridge
[45] Owens Corning, RIZERidge Hip & Ridge Shingles, technical information. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/rizeridge-hip-ridge
[46] TAMKO, TAMKO 12-1/4 x 12 Hip & Ridge, Roofing Accessory Product Data. Checked November 12, 2026. https://www.tamko.com/docs/default-source/data-sheets/tamko-12-1-4x12-hip-ridge-data-sheet-(joplin).pdf
[47] TAMKO, Heritage Designer Ridge, High Profile Ridge Product Data. Checked November 12, 2026. https://www.tamko.com/docs/default-source/data-sheets/tamko-heritage-designer-ridge-data-sheet.pdf
[48] CertainTeed, Technical Data Sheet, DiamondDeck High Performance Synthetic Underlayment. Checked November 12, 2026. https://certainteed.widen.net/content/zrfi9wck6n/pdf/DiamondDeck-TDS-CTRCOMM-015-2608-E.pdf
[49] CertainTeed, RoofRunner Technical Data Sheet. Checked November 12, 2026. https://certainteed.widen.net/content/yd9zj8ldej/pdf/RoofRunnerTDS.pdf
[50] GAF, FeltBuster Synthetic Roofing Felt Sell Sheet. Checked November 12, 2026. https://www.gaf.com/en-us/document-library/documents/data-sheets/feltbuster-sell-sheet-resul183_data-sheet.pdf
[51] IKO, Stormtite Synthetic Underlayment, specifications. Checked November 12, 2026. https://www.iko.com/na/product/stormtite-synthetic-underlayment/
[52] Malarkey, Secure Start Lite, technical specs. Checked November 12, 2026. https://www.malarkeyroofing.com/products/accessories/secure-start-lite/
[53] Malarkey, Secure Start Plus, technical specs. Checked November 12, 2026. https://www.malarkeyroofing.com/products/accessories/secure-start-plus/
[54] Owens Corning, DeckDefense High Performance Synthetic Roof Underlayment, product information. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/deck-defense
[55] Owens Corning, ProArmor Synthetic Roof Underlayment, product information. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/proarmor
[56] Owens Corning, RhinoRoof U20 Synthetic Roofing Underlayment, specifications. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/rhinoroof-u20
[57] Owens Corning, Titanium UDL30 Synthetic Roofing Underlayment, roll specs. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/titanium-udl30
[58] TAMKO, Synthetic Guard, Synthetic Underlayment Product Data. Checked November 12, 2026. https://www.tamko.com/docs/default-source/data-sheets/tamko-synthetic-guard-data-sheet.pdf
[59] Tarco, ASTM Roofing Felts. Checked November 12, 2026. https://www.tarcoroofing.com/asphalt-saturated-organic-felts
[60] CertainTeed, WinterGuard Granular, Sand & Sand X Waterproofing Shingle Underlayment Technical Data Sheet. Checked November 12, 2026. https://certainteed.widen.net/content/kivpxq7tve/pdf/WinterGuardGranular_WinterGuardSand_WInterGuardSandX_TDS_CTRCOMM-015-2405_E.pdf
[61] GAF, WeatherWatch Mineral-Surfaced Leak Barrier Sell Sheet. Checked November 12, 2026. https://www.gaf.com/en-us/document-library/documents/data-sheets/weatherwatch-mineral-surfaced-leak-barrier-sell-sheet-resul103.pdf
[62] IKO, GoldShield Premium Ice and Water Protector, specifications. Checked November 12, 2026. https://www.iko.com/na/product/goldshield-premium-ice-and-water-protector/
[63] IKO, StormShield Ice and Water Protector, specifications. Checked November 12, 2026. https://www.iko.com/na/product/stormshield-ice-and-water-protector/
[64] Malarkey, Arctic Seal, technical specs. Checked November 12, 2026. https://www.malarkeyroofing.com/products/accessories/arctic-seal/
[65] Owens Corning, RhinoRoof Granulated Self-Adhered Underlayment, specifications. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/rhinoroof-granulated
[66] Owens Corning, Titanium PSU30 High-Temp Self-Adhered Underlayment, roll specs. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/titanium-psu30
[67] Owens Corning, WeatherLock Mat Self-Sealing Waterproofing Barrier, typical values. Checked November 12, 2026. https://www.owenscorning.com/en-us/roofing/components/products/weatherlock-mat
[68] TAMKO, Moisture Guard, Ice & Rain Underlayment Product Data. Checked November 12, 2026. https://www.tamko.com/docs/default-source/data-sheets/tamko-moisture-guard-data-sheet.pdf
[69] International Code Council, 2021 IRC, Chapter 8 Roof-Ceiling Construction, R806.2 Minimum vent area. Checked November 12, 2026. https://codes.iccsafe.org/content/IRC2021P2/chapter-8-roof-ceiling-construction

Made with HoneyDoMath.com. Estimates for planning; check product labels and local codes before you buy or build.

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Sources (69)

Underlayment	Width, as printed	Length, as printed
CertainTeed DiamondDeck	4 ft (per CertainTeed's data sheet, checked Nov 12, 2026)	250 ft (per CertainTeed's data sheet, checked Nov 12, 2026)
CertainTeed RoofRunner	4 ft (per CertainTeed's data sheet, checked Nov 12, 2026)	250 ft (per CertainTeed's data sheet, checked Nov 12, 2026)
GAF FeltBuster	48 in (per GAF's published data, checked Nov 12, 2026)	250 ft (per GAF's published data, checked Nov 12, 2026)
IKO Stormtite	48 in (per IKO's product page, checked Nov 12, 2026)	250 ft (per IKO's product page, checked Nov 12, 2026)
Malarkey Secure Start Lite	48 in (per Malarkey's product page, checked Nov 12, 2026)	250 ft (per Malarkey's product page, checked Nov 12, 2026)
Malarkey Secure Start Plus	48 in (per Malarkey's product page, checked Nov 12, 2026)	250 ft (per Malarkey's product page, checked Nov 12, 2026)
Owens Corning DeckDefense	48 in (per Owens Corning's product page, checked Nov 12, 2026)	250 ft (per Owens Corning's product page, checked Nov 12, 2026)
Owens Corning ProArmor	42 in (per Owens Corning's product page, checked Nov 12, 2026)	286 ft (per Owens Corning's product page, checked Nov 12, 2026)
Owens Corning RhinoRoof U20	42 in (per Owens Corning's product page, checked Nov 12, 2026)	286 ft (per Owens Corning's product page, checked Nov 12, 2026)
Owens Corning Titanium UDL30	48 in (per Owens Corning's product page, checked Nov 12, 2026)	250 ft (per Owens Corning's product page, checked Nov 12, 2026)
TAMKO No. 15 felt	36 in (per TAMKO's published data, checked Nov 12, 2026)	144 ft (per TAMKO's published data, checked Nov 12, 2026)
TAMKO No. 30 felt	36 in (per TAMKO's published data, checked Nov 12, 2026)	72 ft (per TAMKO's published data, checked Nov 12, 2026)
TAMKO Synthetic Guard	42 in (per TAMKO's published data, checked Nov 12, 2026)	286 ft (per TAMKO's published data, checked Nov 12, 2026)
Tarco 15# ASTM Specification Felt	36 in (per Tarco's product page, checked Nov 12, 2026)	144 ft (per Tarco's product page, checked Nov 12, 2026)
Tarco 30# ASTM Specification Felt	36 in (per Tarco's product page, checked Nov 12, 2026)	72 ft (per Tarco's product page, checked Nov 12, 2026)

Example: a gable roof

Your project

Shopping list

Save on this device

Saved projects

Worked example: a gable roof

Assumptions

What the list counts

Area one bundle covers, by shingle

Coverage of one bundle where the maker prints it

Starter strip, by product

Hip and ridge cap, by product

Underlayment rolls, by product

Ice barrier rolls, by product

Coverage of one roll where the maker prints it

Why the total is rounded once

Attic ventilation

When the exception figure appears

What the code says about low slopes

Low slopes

When an ice barrier applies

The 2021 IRC ice barrier distances

Ice barrier at the eaves

Common jobs

Questions

How many bundles of shingles do I need?

What is a roofing square?

Why is waste its own line?

Why are the starter and the cap counted separately?

How far up the roof does the ice barrier go?

What is the attic ventilation rule?

Does the calculator give a cost?

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Sources (69)