How to calculate square footage
Square footage is simply the area of a space: its length multiplied by its width. For a rectangular room or plot, measure both sides in feet and multiply. This calculator also works out the total cost when you enter a price per square foot, which is handy for flooring, tiling or paint.
The formula
Square footage = length (ft) x width (ft). Total cost = square footage x price per square foot.
Worked example
A room 12 feet by 10 feet is 120 square feet. At a flooring price of 5 per square foot, that is 600 in materials.
Rooms and other shapes
For a room, measure wall to wall. For an L-shaped space, split it into rectangles, work out each, and add them together. For a whole house, add up the square footage of each room. If you measured in feet and inches, convert the inches to a decimal first, so 6 inches becomes 0.5 feet.
Frequently asked questions
How do I calculate the square footage of a room?
Measure the length and width in feet and multiply them. For an L-shaped room, split it into rectangles, calculate each, and add the results.
How do I handle feet and inches?
Convert the inches to a decimal of a foot first: 6 inches is 0.5 feet, 3 inches is 0.25 feet. Then multiply length by width as usual.
Is this square feet or square metres?
Either. The area is in the same unit you enter, squared. Feet give square feet; metres give square metres.
How do I handle an L-shaped room?
Divide it into rectangles, calculate each area separately, and add them together.
Should I add extra for waste?
Yes. For flooring or tiles, adding about 10% covers cuts, breakages and mistakes.