Square Footage Calculator
Square feet for a room, a whole house, a yard or an odd shape. Enter feet and inches, add as many areas as you need, and get square yards, square meters, acres and cost at once.
Square feet = length × width (in feet). Convert inches by dividing by 12: a room 12 ft 6 in × 10 ft 3 in is 12.5 × 10.25 = 128.1 sq ft. For an L-shape, split it into rectangles and add them. Circles: π × (diameter ÷ 2)². Divide by 9 for square yards, or by 43,560 for acres.
Square footage of common room sizes
| Room | Square feet | Square yards | Square meters |
|---|---|---|---|
| 10 × 10 ft | 100 | 11.1 | 9.3 |
| 10 × 12 ft | 120 | 13.3 | 11.1 |
| 12 × 12 ft | 144 | 16.0 | 13.4 |
| 12 × 14 ft | 168 | 18.7 | 15.6 |
| 14 × 16 ft | 224 | 24.9 | 20.8 |
| 16 × 20 ft | 320 | 35.6 | 29.7 |
| 20 × 20 ft | 400 | 44.4 | 37.2 |
Area conversions
| From | To | Multiply by |
|---|---|---|
| Square feet | Square yards | ÷ 9 |
| Square feet | Square meters | × 0.0929 |
| Square feet | Acres | ÷ 43,560 |
| Square inches | Square feet | ÷ 144 |
| Square meters | Square feet | × 10.764 |
| Acres | Square feet | × 43,560 |
Frequently asked questions
How do I calculate square footage?
Measure the length and width in feet and multiply them. For measurements in feet and inches, turn the inches into a decimal of a foot (divide by 12) first. For irregular rooms, split the space into rectangles, triangles or circles, find each area and add them up.
How do I calculate the square footage of an L-shaped room?
Split the L into two rectangles, measure each one, multiply length × width for each, and add the two results. Add each part as a separate area in the calculator.
How many square feet is a 12 × 12 room?
144 square feet, which is 16 square yards or about 13.4 square meters.
How do I convert square feet to square yards?
Divide by 9, because a square yard is 3 ft × 3 ft. 270 sq ft ÷ 9 = 30 sq yd. Carpet and some sod are sold by the square yard.
How many square feet are in an acre?
43,560 square feet. A half acre is 21,780 sq ft and a quarter acre is 10,890 sq ft.
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Standard geometry: rectangles length × width, triangles base × height ÷ 2, circles π × radius². Conversions: 1 sq yd = 9 sq ft, 1 sq ft = 0.09290304 m² (exact), 1 acre = 43,560 sq ft.