Square footage calculator

Get started

1. Choose the shape of the area. Use outside dimensions for the rectangle border or ring. The sector takes a radius and a central angle.
2. Set the unit next to each measurement. Enter the number of identical areas and optionally the price per selected area unit.
3. Read the net area in square feet and meters. Add a waste allowance under More options to estimate how much to order.

Example

13 ft × 9 ft, quantity 1

117 ft² (10.86965568 m²)

Calculation method

Convert dimensions to a common unit, find the area of one shape, and multiply by quantity. Cost uses area with any selected allowance, converted to the price unit. Border dimensions are measured outside to outside.

The border width b is measured inward from each edge. For a ring, d is the outside diameter. A 13 ft × 9 ft outside rectangle with a 2 ft border has 72 ft² of border per piece.

For a sector, r is radius and θ is the angle in radians after any conversion. In the order formula, q is quantity and w is the percentage allowance.

Calculation mode