Square Footage Calculator (Rectangles, Triangles, Circles)

Calculate square feet for rooms, lots and irregular shapes. Add multiple sections together.

✓ Formula shown✓ No signupUpdated 2026-10-22
Before you buy

Most people under-order. Add the waste allowance shown above, and buy one extra bag or box for touch-ups. Compare current prices for flooring:

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Worked examples
RoomSquare feetSquare meters
10×12 ft120 sq ft11.1 m²
12×14 ft168 sq ft15.6 m²
15×20 ft300 sq ft27.9 m²
20×25 ft500 sq ft46.4 m²
How the calculation works (sources & assumptions)

Rectangle = L × W; circle = π × (d/2)². For L-shaped rooms, split them into rectangles and add. 1 sq ft = 0.0929 m².

FAQ

How do I measure an L-shaped room?

Split it into two rectangles, measure each, and add the areas.

How many square feet is a 12x12 room?

144 sq ft.

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