Square Footage Calculator

Calculate area in square feet for rectangles, circles, and triangles, with optional cost per square foot. The calculator converts feet, yards, inches, meters, or centimeters to feet before applying the selected shape formula.

How to use this calculator

Choose the shape, enter the required dimensions, and select units for each dimension. Add a price per square foot if you want a cost estimate. Rectangle results also include perimeter, which is useful for trim, edging, and layout checks.

Formula

For a rectangle:

$area = length \times width$

For a circle:

$area = \pi \times radius \times radius$

For a triangle:

$area = base \times height \div 2$

A 12 ft by 10 ft rectangle is 120 sq ft with a 44 ft perimeter. At 4 dollars per sq ft, the optional cost result is 480 dollars.

Where square footage is useful

Square footage is the starting point for paint, flooring, mulch beds, tile, concrete pads, and room planning. Use it with the paint calculator, tile calculator, or mulch calculator when a project needs material quantities.