Free tool
Square Footage Calculator
Measure each room or shape, add them up, subtract the areas you will not cover, and get the total in square feet, square yards and square meters.
How we calculate it
- Feet = feet + inches ÷ 12
- Rectangle = length × width; triangle = base × height ÷ 2; circle = 3.1416 × (diameter ÷ 2)²
- Total = the areas you add − the areas you subtract (never below 0)
- With waste = total × (1 + waste %)
- Square yards = ft² ÷ 9; square meters = ft² × 0.09290304; acres = ft² ÷ 43,560
How to use this tool
- Measure each areaMeasure each room or shape in feet and inches. Split odd shapes into rectangles and triangles.
- Add and subtractEnter each one, and tick subtract for closets, islands or openings you will not cover.
- Read the totalGet square feet, square yards and square meters, and a cost if you enter a price.
Frequently asked questions
How do I calculate square footage?
Multiply the length by the width in feet. A room 12 feet by 14 feet is 168 square feet. For an L-shaped room, split it into rectangles, work out each one and add them. A triangle is base times height divided by two, and a circle is 3.1416 times the radius squared.
How do I use feet and inches?
Turn the inches into a fraction of a foot by dividing by 12, then multiply. 12 feet 6 inches is 12.5 feet and 10 feet 9 inches is 10.75 feet, so that room is about 134.4 square feet. Enter feet and inches in separate boxes and the calculator converts them for you.
How much extra should I add for waste?
It depends on the material, the layout and the installer, so the waste field starts at 0 and you choose. Flooring and tile instructions often call for extra to cover cuts and breakage, usually more for diagonal patterns. Check the product's instructions or ask your installer before you order.
How many square feet are in a square yard?
Nine, because a yard is 3 feet and 3 times 3 is 9. Carpet is often sold by the square yard, so divide square feet by 9 to convert. One square foot is about 0.0929 square meters, and one acre is 43,560 square feet.