About this calculator
Square footage is the area of a floor, wall or lot measured in square feet — the basic number behind flooring, paint, sod, real-estate listings and contractor quotes. This calculator multiplies length by width and can add up to three rectangles, which covers L-shaped rooms, rooms with a bay or closet, or several rooms at once.
Enter measurements in feet, inches, yards, meters or centimeters; results are shown in square feet, square yards and square meters.
How to use it
- Measure the length and width of the main rectangle.
- If the space isn’t a simple rectangle, divide it into up to three rectangles and enter each one. Leave unused areas at 0.
- Pick the unit for each measurement from its dropdown — you can mix feet and inches.
- Optionally enter a price per square foot to estimate the cost of flooring, installation or other work.
The formula
Area = length × width
Total = area 1 + area 2 + area 3
Square yards = square feet ÷ 9 · Square meters = square feet × 0.0929
For a room with a missing corner, you can also measure the full outer rectangle and subtract the missing piece — enter it as the only area and subtract the corner yourself.
Worked example
These are the calculator’s starting values and the results they produce:
| Area 1 length | 12 ft |
|---|---|
| Area 1 width | 10 ft |
| Area 2 length (optional) | 0 ft |
| Area 2 width (optional) | 0 ft |
| Area 3 length (optional) | 0 ft |
| Area 3 width (optional) | 0 ft |
| Price per square foot (optional) | $0.00 |
Tips before you buy
- Measure to the nearest inch and round up, not down, when you’re buying materials.
- For flooring, include closets and the space under doors; for paint, measure walls instead of floors.
- A laser distance measure makes long rooms and high ceilings a one-person job.
- Real-estate square footage usually counts finished, heated space only; methods vary by region.
Frequently asked questions
How do I calculate square footage?
Multiply the length by the width, both in feet. A room 12 ft long and 10 ft wide is 120 square feet.
How do I calculate the square footage of an L-shaped room?
Split the L into two rectangles, calculate each area and add them. For example, 12 × 10 ft plus 6 × 8 ft is 120 + 48 = 168 sq ft.
How do I convert inches to square feet?
Multiply length × width in inches and divide by 144. A 96 × 120 in area is 11,520 sq in ÷ 144 = 80 sq ft.
How many square feet are in a square meter?
One square meter is 10.764 square feet, and one square foot is 0.0929 square meters.