How do I calculate an irregular (non-rectangular) room?

Split it into two or more rectangles, calculate the square footage of each piece separately, and add a row for each piece to get the combined total.

Is this the same as the square footage on a real estate listing?

It's the same basic calculation, but official listing square footage often follows specific measurement standards (like measuring exterior walls) that can differ slightly from a simple room-by-room measurement.

Square Footage Calculator

Calculate the total square footage of a room or home from its length and width — add multiple rooms to get a combined total.

Room 1 length (ft)

Width (ft)

Room 2 length (ft)

Width (ft)

Total Square Feet

200 sq ft

Total Square Meters

18.58 m²

How It Works

The area formula

Square footage = length × width, for each rectangular room. Add up every room to get the total square footage of a home or renovation project.

Example

A 10 ft × 12 ft room and an 8 ft × 10 ft room together total 200 square feet.

Common Mistakes

Measuring wall-to-wall instead of the actual usable floor space, which can overstate square footage.
Forgetting irregularly-shaped rooms — split an L-shaped room into two rectangles, calculate each separately, and add them together.

Frequently Asked Questions

How do I calculate an irregular (non-rectangular) room?: Split it into two or more rectangles, calculate the square footage of each piece separately, and add a row for each piece to get the combined total.
Is this the same as the square footage on a real estate listing?: It's the same basic calculation, but official listing square footage often follows specific measurement standards (like measuring exterior walls) that can differ slightly from a simple room-by-room measurement.