Square Footage Calculator
Enter the shape and its dimensions to get the area in square feet, plus square yards, square meters and acres. Add a quantity for repeated areas and a waste allowance for ordering material.
Result
- Square yards
- 13.33 sq yd
- Square meters
- 11.15 m²
- Square inches
- 17,280 sq in
- Acres
- 0.00275 acres
Formula
- Rectangle: area = length × width
- Circle: area = π × (diameter ÷ 2)²
- Triangle: area = ½ × base × height
- Trapezoid: area = ½ × (a + b) × height
- 1 sq yd = 9 sq ft · 1 m² = 10.7639 sq ft · 1 acre = 43,560 sq ft
How the Square Footage Calculator works
Square footage is the area of a surface measured in square feet. Measure each dimension in the same unit, multiply according to the shape, and convert the result. The calculator converts every entry to meters internally using the exact definition 1 ft = 0.3048 m, so mixed units such as feet and inches give exact results.
For an L-shaped or irregular room, split it into rectangles, calculate each one, and add the results. The quantity field multiplies one shape by a count, which is handy for identical rooms or panels.
Worked example
A room 12 ft long and 10 ft wide has an area of 12 × 10 = 120 sq ft. That equals 120 ÷ 9 = 13.33 sq yd, or 11.15 m².
Frequently asked questions
How do I calculate square feet from inches?
Multiply the length in inches by the width in inches and divide by 144, because one square foot is 12 × 12 = 144 square inches. You can also pick inches as the unit and the calculator converts for you.
How many square feet are in a square yard?
One square yard is 3 ft × 3 ft = 9 square feet. Divide square feet by 9 to get square yards.
How much waste should I add?
For flooring and tile, 5 to 10 percent is typical for straight layouts and 15 percent for diagonal patterns. Enter the percentage in the waste field to see the larger order quantity.
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