Square Footage Calculator
- Updated
- Imperial and metric
- Free, no sign-up
Results
Total area 215 ft² (19.97 m²)
| Area | Shape | ft² | m² |
|---|---|---|---|
| Area 1 | Rectangle or square | 175 | 16.26 |
| Area 2 | Rectangle or square | 40 | 3.72 |
How to use the square footage calculator
- Choose how many areas you want to add. Split an irregular room into simple shapes rather than guessing an average size.
- Pick a shape for each area and enter its dimensions. Use the second box for any extra inches (or centimeters), so 12 ft 6 in is 12 and 6.
- Set an area to Subtract to take out something you won't cover, such as a fireplace hearth, a kitchen island or a stair opening.
- Optionally add a waste percentage and your price per square foot (or square meter) to see the amount to buy and its cost.
Square footage formulas
L-shape = overall length × overall width − notch length × notch width
Circle = π × diameter² ÷ 4
Triangle = base × height ÷ 2
Trapezoid = (parallel side a + parallel side b) ÷ 2 × height
Square meters = square feet ÷ 10.7639 · Square yards = square feet ÷ 9 · Acres = square feet ÷ 43,560
Square footage is the area of a flat surface measured in square feet: one square foot is a square 1 ft on each side. Convert every measurement to the same unit before multiplying. Inches become feet when you divide by 12, so 6 inches is 0.5 ft, not 0.6 ft. The calculator does this for you. The L-shape formula treats the room as one large rectangle with a rectangular corner missing, which is usually quicker to measure than two separate rectangles. For a triangle or trapezoid, the height is measured at right angles to the base or between the parallel sides, not along a sloping side.
Worked example: an L-shaped living room
The room measures 20 ft 6 in by 15 ft overall, with an 8 × 6 ft corner taken up by the entry hall. 20 ft 6 in is 20.5 ft, so the full rectangle is 20.5 × 15 = 307.5 ft². Removing the 48 ft² notch leaves 259.5 ft². A 5 × 2 ft hearth won't get new flooring, so subtracting it gives 249.5 ft², which is 23.18 m² or 27.72 yd². With 10% extra for cuts you would buy about 274.5 ft², and at an example price of $4.00 per ft² the flooring costs about $1,098.
Square footage of common room sizes
| Room | Square feet | Square meters | Square yards |
|---|---|---|---|
| 10 × 10 ft | 100 ft² | 9.29 m² | 11.11 yd² |
| 10 × 12 ft | 120 ft² | 11.15 m² | 13.33 yd² |
| 12 × 12 ft | 144 ft² | 13.38 m² | 16 yd² |
| 12 × 14 ft | 168 ft² | 15.61 m² | 18.67 yd² |
| 12 × 16 ft | 192 ft² | 17.84 m² | 21.33 yd² |
| 14 × 16 ft | 224 ft² | 20.81 m² | 24.89 yd² |
| 16 × 20 ft | 320 ft² | 29.73 m² | 35.56 yd² |
| 20 × 20 ft | 400 ft² | 37.16 m² | 44.44 yd² |
| 20 × 30 ft | 600 ft² | 55.74 m² | 66.67 yd² |
Area unit conversions
| Unit | Equals |
|---|---|
| 1 square foot | 144 in² · 0.0929 m² |
| 1 square meter | 10.764 ft² · 1.196 yd² |
| 1 square yard | 9 ft² · 0.8361 m² |
| 1 acre | 43,560 ft² · 4,046.9 m² |
| 1 hectare | 10,000 m² · 2.471 acres |
Measuring tips and common mistakes
- Measure wall to wall at floor level. Baseboards and trim are ignored for flooring; measure to the wall itself, and include closets that get the same floor.
- Don't add feet and inches as decimals. 10 ft 6 in is 10.5 ft. Typing 10.6 adds about 1 inch too much on every side you measure that way.
- Round curves into shapes you know. A bay window is roughly a trapezoid, and a round patio is a circle: a 12 ft circle covers 113.1 ft², not 144 ft².
- Living area is not the same as floor area. Listings and appraisals follow their own rules for which spaces count (garages, basements, low ceilings), so use this calculator for materials, not to argue with a listing.
- Buy by the box. Flooring and tile are sold in boxes covering a fixed area, so round up after adding waste.
Ready to order materials? Use the flooring calculator for boxes and baseboard, the tile calculator for tiles by pattern, or the drywall calculator for walls and ceilings. For a single shape with more options, try the area calculator.
Frequently asked questions
How do I calculate square footage?
Measure the length and width in feet and multiply them. A room 12 ft wide and 14 ft long is 12 × 14 = 168 square feet. For an irregular space, split it into rectangles, triangles or circles, work out each one and add them together.
How do I measure an L-shaped room?
Measure the overall length and width as if the room were a full rectangle, then subtract the missing corner. A room 20 × 15 ft overall with an 8 × 6 ft corner missing is 300 − 48 = 252 square feet.
How do I enter feet and inches?
Convert the inches to a fraction of a foot by dividing by 12, then multiply. 12 ft 6 in is 12.5 ft, so a 12 ft 6 in × 10 ft room is 125 square feet. In the calculator, type 12 in the feet box and 6 in the inches box.
How many square feet are in a square meter, a square yard and an acre?
One square meter is about 10.764 square feet, one square yard is exactly 9 square feet and one acre is 43,560 square feet (about 4,047 square meters). To turn square feet into square meters, divide by 10.764.
How do I find the square footage of a circle?
Multiply π by the diameter squared and divide by 4 (or use π × radius²). A round patio 12 ft across covers π × 144 ÷ 4 ≈ 113.1 square feet, a little over three-quarters of a 12 × 12 ft square.