Square Footage Calculator (Square Feet of Any Room or Shape)
Type each room's length and width in feet and inches, as you measured them, and get the floor area of all your rooms added together and rounded once, with every step shown in the worked example.
Estimates for planning, not professional advice. Read the full notice.
Floor: shape and size
Skip the drawingDrag a round corner to move it. The small hollow diamond on a side is its curve handle: drag it across the side to curve the side (it is not a corner). To add a corner (a new point), tap the side itself, then choose Add a point here. Tapping a corner or a side opens its actions. Drag empty space to move the view; pinch, or Ctrl and the mouse wheel, to zoom. The keys are listed under Keys.
Keys
- Tab
- next corner; each says how far it is from corner 1
- Arrow keys on a corner
- move it one square; ten with Shift; 1/16 in with Alt
- Delete or Backspace
- remove the corner; its two sides join in one straight side
- + on a corner
- add a corner halfway along the next side
- Arrow keys on the drawing
- move the view; farther with Shift
- + and - on the drawing
- zoom in and out
- 0 on the drawing
- show the whole shape
- Ctrl+Z (Cmd+Z on a Mac)
- undo, except inside a typed field (it keeps its own)
- Ctrl+Shift+Z or Ctrl+Y
- redo
- Escape while dragging
- put it back where it was
- Enter on a corner or side
- go to its actions
- Escape in the actions
- close them and go back to the drawing
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- Area
- 144 ft²
- Perimeter
- 48 ft
- Cut-out edges
No area until the shape is fixed.
Estimate for planning, from what you entered and the product data shown. Check product labels and your supplier before you buy.
Shape: Rectangle Change
Sides
Corners
Cut-outs
Feet and inches, like 12' 6"
Example sizes
- First room, length
- 12 ft
- First room, width
- 12 ft
- Second room, length
- 11 ft
- Second room, width
- 10 ft
- Closet, length
- 6 ft
- Closet, width
- 5 ft
The result shown is worked out from these sizes.
Example: three rooms added together
284 ft²
Your project
Enter a size to see your total.
New rooms start at 12 ft × 12 ft until you change them.
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.
Worked example: three rooms added together
Show the working
- First room 12 ft × 12 ft = 144 ft²
- Second room 10 ft × 11 ft = 110 ft²
- Closet 5 ft × 6 ft = 30 ft²
- Add the rooms, round once 144 ft² + 110 ft² + 30 ft² = 284 ft²
Feet and inches as you measured them
How sizes typed in feet and inches, and a size typed with a decimal point, are read and multiplied
| As typed | Width read as | Length read as | Exact area, square inches | Area, square feet |
|---|---|---|---|---|
| 12' 6" × 10' 3" | 12 ft 6 in | 10 ft 3 in | 18,450 in² | 128.13 ft² |
| 10.3 × 12, as decimal feet | 10 ft 3 5/8 in | 12 ft | 17,798.4 in² | 123.6 ft² |
| 10.3 × 12, as feet and inches | 10 ft 3 in | 12 ft | 17,712 in² | 123 ft² |
A size with a decimal point can mean decimal feet or feet and inches. The calculator shows both readings and asks which one was meant; the area is exact first and shown to two places at the end.
Measuring cases
Floor area in square feet, and the walls' length, for common sizes
| Room | Area, square feet | Perimeter, feet |
|---|---|---|
| 12 ft × 12 ft | 144 ft² | 48 ft |
| 12' 6" × 10' 3" | 128.13 ft² | 45.5 ft |
| 13 ft × 11 ft 6 in | 149.5 ft² | 49 ft |
| 30 in × 18 in | 3.75 ft² | 8 ft |
| 200 ft × 300 ft | 60,000 ft² | 1,000 ft |
| 3 rooms of 10 ft × 11 ft | 330 ft² | 42 ft |
The perimeter is one room's walls; for the repeated room the area is all the copies together.
A large area in acres
The same large area in square feet and in acres
| Area | Square feet | Acres |
|---|---|---|
| 200 ft × 300 ft | 60,000 ft² | 1.38 acres |
Questions
How do I work out the square feet of a room?
Multiply the room's length by its width, both in feet. A size in feet and inches is read as a fraction of a foot first, so six inches counts as half a foot.
How do I enter feet and inches?
Type them the way you measured: the feet with a foot mark, then the inches with an inch mark. If a size typed with a decimal point could also mean feet and inches, the calculator shows both readings and you pick the one you meant.
How do I add up several rooms or a whole floor?
Work out each room's floor area, add the exact areas together, and round the total once at the end. Rounding every room first can move the total by a fraction of a square foot. A room that repeats can be entered once with a number of copies.
How do I change square feet into square yards?
Divide the square feet by the number of square feet in one square yard, which is three feet by three feet. The calculator on this page shows square feet only, so that one division is yours to do by hand.
How do I work out a cost per square foot?
The price is your own, from your supplier or installer. Multiply it by the total area shown here, in the same unit the price is quoted in.