Square Footage Calculator
Square footage is length × width for a rectangle, ½ × base × height for a triangle, and π × radius² for a circle. Pick a shape, enter the dimensions, and total as many areas as you need.
How to measure square footage
Pick the shape that matches your area and enter its dimensions:
- Rectangle or square — length × width
- Triangle — ½ × base × height
- Circle — π × radius² (enter the diameter; the tool halves it)
Measure in feet for a direct square-foot answer, or switch units and the calculator converts for you.
Totaling an irregular space
Real rooms are rarely a single rectangle. Break the floor into simple shapes, work out each one, and add them together. The quantity field totals identical areas — handy for repeated bays or several matching rooms.
What to do with the number
Square footage feeds almost every material estimate. Once you have it, drop it straight into the tile calculator or flooring calculator to turn area into boxes, tiles, and cost.
Frequently asked
How do I calculate square footage?
For a rectangle, multiply length by width. For a triangle, take half the base times the height. For a circle, multiply pi by the radius squared. All give the area in square feet when you measure in feet.
How do I find the square footage of an irregular room?
Split the room into rectangles, triangles, and partial circles, calculate each, and add them up. Use the quantity field to total several identical sections at once.
How do I convert square feet to square yards?
Divide square feet by 9. The calculator also shows square meters, dividing square feet by 10.764.