Grout Calculator for Tile
Enter the area and pick your tile size and joint from the maker's printed coverage chart, and get the pounds of grout and the bags to buy, rounded up once. A tile size or joint the chart does not print has no figure here.
Estimates for planning, not professional advice. Read the full notice.
Example: a tiled floor
1 25 lb bag
- Grout needed 5.7 lb
- Bags 1 × 25 lb bag
Estimate for planning, from what you entered and the product data shown. Check product labels and your supplier before you buy.
Your project
Enter a size to see your total.
Each product is rounded up once for the whole project, so the total can be less than the items bought alone added together. A line counted from a cut layout (sheets, boards or tiles laid out piece by piece) is counted for each item and added.
Shopping list
| Item | Size | Buy |
|---|---|---|
| Sanded grout, by the bag | 25 lb bag | 1 |
Save on this device
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Worked example: a tiled floor
Show the working
- Bags' worth of area: divide the area by the chart's coverage 80 ft² ÷ 348 sq ft = 0.23 bags
- Pounds: times the weight of a bag 0.23 bags × 25 lb = 5.7 lb
- Round up once, to whole bags 5.7 lb ÷ 25 lb = 1 × 25 lb bag
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 |
|---|---|---|
| Extra grout on top of the chart | 0% | |
| Default Our assumption: none. Add a percentage if you want a cushion; check your label or supplier. | ||
| Coverage of one bag at the starting tile and joint | 348 ft²[1] | |
| Square feet one 25 lb bag covers for 12x12x3/8 inch tile, at each of five joint widths, per the maker's coverage chart. | ||
| Bag size the chart is printed for | 25 lb[1] | |
| Square feet one 25 lb bag covers for 12x12x3/8 inch tile, at each of five joint widths, per the maker's coverage chart. | ||
Feet and inches, like 12' 6"
The maker's grout coverage chart
Square feet one bag of sanded grout covers, by tile size and joint width, as the maker prints it
| Tile size (width, length, thickness, in inches) | 1/8 in joint | 3/16 in joint | 1/4 in joint | 3/8 in joint | 1/2 in joint |
|---|---|---|---|---|---|
| 1x1x1/4 | 54 ft² | 40 ft² | 33 ft² | 27 ft² | 24 ft² |
| 2x2x1/4 | 96 ft² | 68 ft² | 54 ft² | 40 ft² | 33 ft² |
| 3x3x1/4 | 138 ft² | 96 ft² | 74 ft² | 54 ft² | 43 ft² |
| 4.25x4.25x1/4 | 192 ft² | 131 ft² | 101 ft² | 71 ft² | 56 ft² |
| 6x6x1/4 | 266 ft² | 181 ft² | 139 ft² | 96 ft² | 75 ft² |
| 8x8x3/8 | 234 ft² | 158 ft² | 121 ft² | 83 ft² | 64 ft² |
| 12x12x3/8 | 348 ft² | 234 ft² | 177 ft² | 121 ft² | 92 ft² |
| 16x16x3/8 | 462 ft² | 310 ft² | 234 ft² | 158 ft² | 121 ft² |
| 18x18x3/8 | 518 ft² | 348 ft² | 262 ft² | 177 ft² | 135 ft² |
| 20x20x3/8 | 574 ft² | 385 ft² | 291 ft² | 196 ft² | 149 ft² |
| 24x24x3/8 | 688 ft² | 461 ft² | 348 ft² | 234 ft² | 177 ft² |
Figures in the 1/8 in joint, 3/16 in joint, 1/4 in joint, 3/8 in joint and 1/2 in joint columns are per Custom Building Products' product page, checked Nov 12, 2026.
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.
Source: [1]
These are the chart's own rows and columns. Another maker's chart differs, and the maker says the chart is for estimating.
Pounds of grout for the example floor, by tile size and joint
Pounds of grout for the example area at every chart tile size and joint width, from the chart's coverage
| Tile size (width, length, thickness, in inches) | 1/8 in joint | 3/16 in joint | 1/4 in joint | 3/8 in joint | 1/2 in joint |
|---|---|---|---|---|---|
| 1x1x1/4 | 37 lb | 50 lb | 60.6 lb | 74.1 lb | 83.3 lb |
| 2x2x1/4 | 20.8 lb | 29.4 lb | 37 lb | 50 lb | 60.6 lb |
| 3x3x1/4 | 14.5 lb | 20.8 lb | 27 lb | 37 lb | 46.5 lb |
| 4.25x4.25x1/4 | 10.4 lb | 15.3 lb | 19.8 lb | 28.2 lb | 35.7 lb |
| 6x6x1/4 | 7.5 lb | 11 lb | 14.4 lb | 20.8 lb | 26.7 lb |
| 8x8x3/8 | 8.5 lb | 12.7 lb | 16.5 lb | 24.1 lb | 31.3 lb |
| 12x12x3/8 | 5.7 lb | 8.5 lb | 11.3 lb | 16.5 lb | 21.7 lb |
| 16x16x3/8 | 4.3 lb | 6.5 lb | 8.5 lb | 12.7 lb | 16.5 lb |
| 18x18x3/8 | 3.9 lb | 5.7 lb | 7.6 lb | 11.3 lb | 14.8 lb |
| 20x20x3/8 | 3.5 lb | 5.2 lb | 6.9 lb | 10.2 lb | 13.4 lb |
| 24x24x3/8 | 2.9 lb | 4.3 lb | 5.7 lb | 8.5 lb | 11.3 lb |
Each cell is the example area divided by that row and column's printed coverage, times the weight of a bag, before rounding up to whole bags.
Questions
How many square feet does a bag of grout cover?
It depends on the tile size and the joint width. The first table gives the maker's printed coverage for one bag at each size and joint, and the calculator reads the row and column you pick.
Why does the calculator offer only the chart's tile sizes and joints?
The coverage comes from the maker's chart and nothing is worked out between its rows. A size or joint the chart does not print has no figure from this tool, so ask the maker or your supplier for it.
Do makers agree on how much grout a job takes?
No. Each maker prints its own chart and calls it an estimate, so another brand's grout can come out higher or lower. The extra grout row in the assumptions adds a cushion if you want one.
Sources (1)
-
Polyblend Plus Sanded Grout, coverage chart (opens in new tab), Custom Building Products, Product page, coverage chart.
Manufacturer data.
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 12″ x 12″ x 3/8″ … 348 ft² … 234 ft² … 177 ft² … 121 ft² … 92 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 1″ x 1″ x 1/4″ … 54 ft² … 40 ft² … 33 ft² … 27 ft² … 24 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 2″ x 2″ x 1/4″ … 96 ft² … 68 ft² … 54 ft² … 40 ft² … 33 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 3″ x 3″ x 1/4″ … 138 ft² … 96 ft² … 74 ft² … 54 ft² … 43 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 4.25″ x 4.25″ x 1/4″ … 192 ft² … 131 ft² … 101 ft² … 71 ft² … 56 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 6″ x 6″ x 1/4″ … 266 ft² … 181 ft² … 139 ft² … 96 ft² … 75 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 8″ x 8″ x 3/8″ … 234 ft² … 158 ft² … 121 ft² … 83 ft² … 64 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 16″ x 16″ x 3/8″ … 462 ft² … 310 ft² … 234 ft² … 158 ft² … 121 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 18″ x 18″ x 3/8″ … 518 ft² … 348 ft² … 262 ft² … 177 ft² … 135 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 20″ x 20″ x 3/8″ … 574 ft² … 385 ft² … 291 ft² … 196 ft² … 149 ft²”
“For 25 lb. bag of Polyblend in ft² (m²) per bag … 24″ x 24″ x 3/8″ … 688 ft² … 461 ft² … 348 ft² … 234 ft² … 177 ft²”
“Chart for estimating purposes. Coverage may vary based on installation practices and jobsite conditions.”
Per Custom Building Products' product page, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 1)
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] Custom Building Products, Polyblend Plus Sanded Grout, coverage chart. Checked November 12, 2026. https://www.custombuildingproducts.com/products/polyblendplus-sanded-grout-2