Home › Calculators › Square Footage Calculator
Square Footage Calculator
Pick the shape, enter the measurements in feet, and get the area in square feet. This is the starting number behind paint, tile, flooring, mulch and heating calculations, so it is worth getting right once and reusing everywhere.
How This Calculator Works
A rectangle's area is length times width. A circle's area is pi times the radius squared, and the calculator takes the diameter because that is what you can measure across a round patio or bed. A triangle's area is base times height divided by two. Measure in feet and decimals (6 inches is 0.5 ft) for clean results.
Worked Example
A room 12 ft 6 in by 10 ft is 12.5 by 10, which is 125 square feet. A round bed 10 feet across has a radius of 5, so pi times 25 is about 78.5 square feet. An L-shaped room is just two rectangles: calculate each and add them.
Decimal feet conversion for inches
| Item | Figure |
|---|---|
| 3 inches | 0.25 ft |
| 6 inches | 0.50 ft |
| 9 inches | 0.75 ft |
| 4 inches | 0.33 ft |
| 8 inches | 0.67 ft |
Frequently Asked Questions
How do I calculate square footage of an L-shaped room?
Split it into two rectangles at the step in the L, calculate each area, and add them. The same split and add method works for any irregular floor.
Do I include closets and alcoves?
For flooring and paint, yes if they are being finished the same way: measure them as their own small rectangles and add them in.
How do I convert square feet to square yards?
Divide by 9. Carpet and some flooring is sold by the square yard, so 270 square feet is 30 square yards.
Should I round up when ordering materials?
Always. Calculate the exact area here, then let the specific material calculator add its waste allowance. Ordering to the exact square foot guarantees running short.