📐 Square Footage Calculator
How to calculate square footage
Square footage is simply an area measured in square feet. For a rectangular room or floor, multiply the length by the width: a space that is 12 feet long and 10 feet wide is 120 square feet. This calculator does that instantly and, because you can enter measurements in feet, inches, yards or metres, it converts everything to square feet, square metres and square yards for you.
Not every space is a neat rectangle. Switch to the circle tab for round patios or rugs — the tool uses π × radius² — or the triangle tab for angled corners, using ½ × base × height. If your project spans several identical rooms, set the number of areas and the total is multiplied automatically. For rooms of different sizes, calculate each one and add the results.
Estimating material cost
Enter a price per square foot and the calculator returns an estimated material cost — handy for flooring, tile, turf, carpet or paint. For flooring and tile, add a 5–10% waste allowance for cuts and breakage; our tile calculator does this automatically. Always round up when buying materials so you're not left short mid-job.
How do I calculate the square footage of a room?
Measure the length and width in feet and multiply them. This calculator also converts from inches, yards or metres for you.
How many square feet is a 10x10 room?
100 square feet — length (10 ft) multiplied by width (10 ft).
Can I add several rooms together?
Yes. Use the “number of areas” field for identical rooms, or calculate each room separately and add the totals for mixed sizes.
Related tools: Tile & Flooring · Paint Calculator · Concrete Calculator.