Square footage calculator
Calculate the area of a rectangular, circular or triangular room, floor or lot in square feet, square meters and square yards, with a waste allowance and material cost.
Fix the highlighted fields to see your result.
- Square meters
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- Square feet
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- Square yards
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- With waste
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- Estimated material cost
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How it is calculated
Rectangle = length × width · Circle = π × (diameter ÷ 2)² · Triangle = base × height ÷ 2
1 m² = 10.7639 sq ft and 1 sq yd = 9 sq ft. Waste is added as a percentage of the area.
Assumptions and limitations
- All measurements must be in the same unit.
- For irregular shapes, split the space into simple shapes and add them.
This tool is educational and provides estimates. It is not a credit offer or financial advice. Actual terms are set by each institution.
Frequently asked questions
How do I calculate square footage?
For a rectangle, multiply length by width in feet. A 12 ft × 10 ft room is 120 square feet. For an L-shaped room, split it into rectangles and add them up.
How do I convert square feet to square meters?
Divide by 10.7639. 120 sq ft ≈ 11.15 m². One square meter is about 10.76 square feet.
How much extra flooring should I buy?
Installers often recommend 5% to 10% extra for cuts and waste, and more for diagonal layouts. Ask your supplier or installer.