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Square footage calculator

Split the space into simple shapes and add them up.

Enter your numbers to see the result.

Almost every material estimate starts with square feet: flooring, paint, sod, concrete, roofing. Odd rooms are just simple shapes added together.

Formulas

  • Rectangle: length x width.
  • Triangle: base x height / 2.
  • Circle: 3.1416 x diameter² / 4.

An L-shaped room is two rectangles. A bay window is a rectangle plus two triangles.

Conversions

  • 1 square yard = 9 sq ft (carpet is often priced this way).
  • 1 square meter = 10.764 sq ft.
  • 1 acre = 43,560 sq ft.

Measuring tips

Measure to the nearest inch and convert: 6 in is 0.5 ft, 3 in is 0.25 ft. For flooring, measure wall to wall and include closets you are covering.