Square Footage Calculator
Add up the area of several rooms or sections, take away cutouts, and see the total in square feet, square yards, square meters and acres.
Tip: mark a section as “Subtract” for areas you will not cover, such as a closet, a fireplace hearth or a kitchen island.
How to calculate square footage
Square footage is the area of a flat surface measured in square feet. For any rectangle or square, measure the length and the width in feet and multiply them.
Square feet = length (ft) × width (ft)
ExampleA bedroom is 14 ft long and 12 ft wide. 14 × 12 = 168 square feet.
If you measured in inches, divide each measurement by 12 first, or multiply the inches together and divide by 144. If you measured in yards, multiply the square yards by 9. If you measured in meters, multiply the square meters by 10.764. The calculator does these conversions for you when you change the unit.
Square footage of common room sizes
These are the areas of some common room sizes, so you can check your result at a glance.
| Room size (ft) | Square feet | Square yards | Square meters |
|---|---|---|---|
| 8 × 10 | 80 | 8.89 | 7.43 |
| 10 × 10 | 100 | 11.11 | 9.29 |
| 10 × 12 | 120 | 13.33 | 11.15 |
| 12 × 12 | 144 | 16 | 13.38 |
| 12 × 14 | 168 | 18.67 | 15.61 |
| 12 × 15 | 180 | 20 | 16.72 |
| 14 × 16 | 224 | 24.89 | 20.81 |
| 15 × 20 | 300 | 33.33 | 27.87 |
| 20 × 20 | 400 | 44.44 | 37.16 |
| 24 × 24 | 576 | 64 | 53.51 |
How to measure an L-shaped or irregular room
Most rooms that are not a plain rectangle can be split into rectangles. Work out each one and add them together.
- Sketch the room and draw lines that split it into rectangles.
- Measure the length and width of each rectangle.
- Multiply to get the area of each rectangle.
- Add the areas together. In the calculator, use Add a section for each rectangle.
ExampleAn L-shaped room has a main area of 14 ft by 12 ft and a bay of 5 ft by 6 ft. The main area is 168 sq ft and the bay is 30 sq ft, so the room is 168 + 30 = 198 square feet.
For angled walls or curves, use triangles and circles instead. Our area calculator handles those shapes, and you can add the results to your total.
Subtracting areas you will not cover
If part of the floor will not get the new material, measure it and take it away. Typical examples are a kitchen island, a fireplace hearth, a stairwell opening or built-in cabinets. In the calculator, add the area as a section and set its type to Subtract.
How much extra to allow for waste
Materials such as flooring, tile and carpet have to be cut to fit, and some pieces are damaged or unusable. The usual approach is to add a percentage to the measured area. These are common rules of thumb, and the right figure depends on the material and the layout.
| Layout | Common allowance |
|---|---|
| Straight layout in a simple rectangular room | 5–10% |
| Diagonal layout, or a room with many corners | 10–15% |
| Herringbone and other patterns | 15% or more |
ExampleFor the 198 sq ft room above with a 10% allowance: 198 × 1.10 = 217.8, so you would order at least 218 square feet.
Converting square feet to other units
| To convert square feet to | Do this | 200 sq ft equals |
|---|---|---|
| Square yards | divide by 9 | 22.22 sq yd |
| Square meters | multiply by 0.092903 | 18.58 sq m |
| Square inches | multiply by 144 | 28,800 sq in |
| Acres | divide by 43,560 | 0.0046 acres |
Tips for measuring accurately
- Measure along the floor, wall to wall, at the longest and widest points.
- Measure each dimension twice. If the two readings differ, measure again.
- Write down feet and inches, then convert inches to a decimal by dividing by 12. For example, 12 ft 6 in is 12.5 ft.
- Round measurements up, not down, so you do not come up short.
- Keep your sketch with the measurements on it. It is useful when you order and when you install.
Results are estimates based on the numbers you enter. Confirm quantities with your supplier, installer or contractor before ordering.
Frequently asked questions
How do I calculate square footage?
Measure the length and the width in feet and multiply them. A room 14 ft long and 12 ft wide is 14 × 12 = 168 square feet.
How do I find the square footage of an L-shaped room?
Split the room into two rectangles, work out each one, and add them together. In the calculator, use “Add a section” for the second rectangle.
How many square feet is a 12×12 room?
A 12 ft by 12 ft room is 144 square feet. A 10×10 room is 100 square feet and a 12×15 room is 180 square feet.
Should I include closets?
It depends on what you are covering. If the closet floor gets the same flooring, add it as another section. If not, leave it out.
How much extra flooring should I order?
Many installers allow roughly 5–10% extra for straight layouts and 10–15% for diagonal or patterned layouts. The right figure depends on the material and the room, so check with your supplier or installer.
How many square feet are in an acre?
One acre is 43,560 square feet. The calculator shows the acre value of your total automatically.
How do I convert square feet to square meters or square yards?
Multiply square feet by 0.092903 to get square meters, or divide by 9 to get square yards. For example, 200 sq ft is about 18.58 sq m, or 22.22 sq yd.
Is this the same square footage used in real estate listings?
Not necessarily. Listings and appraisals can follow specific measuring rules that include or exclude certain areas. This calculator is for estimating materials and planning projects, not for appraisals or legal measurements.