How to use the square footage calculator
- Pick your units. Feet or meters. The result always shows square feet, square meters and square yards.
- Measure each section. Measure length and width wall to wall at floor level. Turn inches into feet by dividing by 12, so 6 inches is 0.5 ft.
- Split awkward rooms. Break an L shaped room into two rectangles, and add a triangle or circle for angled walls and round areas.
- Add every room. Use + Rectangle for each extra room to total a whole floor or apartment.
- Add a price. Enter a cost per square foot to see a quick estimate for flooring, carpet or a contractor quote.
How to calculate square footage
For a rectangular room, measure the length and the width in feet and multiply them. A room 12 feet long and 14 feet wide is 168 square feet. Measure wall to wall at floor level, and round to the nearest inch or centimeter.
For other shapes, use the matching formula, which the calculator applies for you:
- Rectangle or square: length times width.
- Triangle: base times height, divided by two.
- Circle: 3.1416 times the radius squared, or 0.785 times the diameter squared.
Feet and inches: how to enter them
Tape measures give feet and inches, but square footage needs decimal feet. Divide the inches by 12 and add them to the feet: 11 ft 6 in is 11.5 ft, and 13 ft 3 in is 13.25 ft. That room is 11.5 times 13.25, which is 152.4 square feet. Common conversions: 3 in is 0.25 ft, 4 in is 0.33 ft, 6 in is 0.5 ft, 8 in is 0.67 ft and 9 in is 0.75 ft.
Worked examples: square footage of real rooms
Real results from the calculator above.
| Room | Sections entered | Square feet | Square meters | Square yards |
|---|---|---|---|---|
| 12x12 bedroom | 12 x 12 ft | 144 | 13.38 | 16 |
| Room in feet and inches | 11 ft 6 in x 13 ft 3 in (11.5 x 13.25) | 152.4 | 14.16 | 16.9 |
| L shaped living room | 12 x 14 ft plus 8 x 6 ft | 216 | 20.07 | 24 |
| Room with an angled bay | 12 x 14 ft plus a triangle, base 6 ft, height 2 ft | 174 | 16.17 | 19.3 |
| Multiple rooms (whole floor) | 12 x 14, 10 x 12 and 15 x 20 ft | 588 | 54.63 | 65.3 |
| Round patio | Circle, 10 ft across | 78.5 | 7.3 | 8.7 |
| Metric bedroom | 4 x 3.5 m | 150.7 | 14 | 16.7 |
With a price of 4.50 per square foot, the whole floor of 588 square feet comes to an estimate of 2,646 before waste. For flooring, add 5 to 20 percent for cuts, which the flooring calculator does for you.
Measuring L shaped and irregular rooms
Split any irregular room into simple shapes. An L shaped room becomes two rectangles: measure each one separately, calculate its area and add them together. A room with a bay window is a rectangle plus a small rectangle or trapezoid. A room with an angled wall is a rectangle plus a triangle. Add each piece as its own section above and the calculator totals them.
Square feet, meters and yards
| To convert | Multiply by |
|---|---|
| Square feet to square meters | 0.0929 |
| Square meters to square feet | 10.764 |
| Square feet to square yards | 0.1111 (divide by 9) |
| Square yards to square feet | 9 |
Carpet is often priced per square yard in the US, while tile, laminate and paint coverage use square feet, and most of the world uses square meters. The calculator shows all three so you can compare quotes easily.
What to do with the number
Total floor area is the base for most home projects. Add a waste allowance before ordering flooring or tile, which our flooring calculator and tile calculator do automatically. The same length and width also tell you how big a rug the room can take: enter them in the rug size calculator to see the size that leaves an even border of floor, with a to scale plan. For inspiration, see our budget home improvement ideas and small space home office ideas.
