Building & DIY

Square Footage Calculator (multi-shape)

Finds square footage for a rectangle, triangle, circle, or trapezoid. You can enter dimensions in feet, inches, yards, meters, or centimeters and read the area in several units, including acres.

How to use
  1. Pick the shape you are measuring.
  2. Enter the dimensions and choose your input unit.
Room size
Total area
120.00 ft²

12 ft × 10 ft rectangle

Square metres
11.148 m²
Square yards
13.33 yd²
Square inches
17,280 in²
Square cm
111,484 cm²
Acres
0.00275 ac
Estimates only, allow for waste and confirm against local building codes and supplier specs.
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How it's calculated

Rectangle A = L × W ; Triangle = ½ b h ; Circle = π r² ; Trapezoid = ½ (b₁ + b₂) h

A = area; L,W = length and width; b = base, h = height; r = radius; b₁,b₂ = parallel sides. Output is converted to ft², m², yd², in² and acres.

Common questions

How do I find the square footage of a room?

For a rectangular room, multiply the length by the width in feet. A 12 ft by 10 ft room is 120 square feet.

Can I mix units like feet and inches?

Convert each dimension to the same unit first. This tool lets you enter inches, yards, meters, or centimeters and handles the conversion for you.