How to Calculate Square Footage of a Room or House

By Jorge Sanchez · April 20, 2026 · 5 min read

Whether you're buying flooring, calculating paint coverage, or listing a home, knowing the square footage is essential. Here's how to do it accurately for any room shape.

Rectangle or Square Room

Example: A living room that is 14 ft long and 12 ft wide = 168 sq ft.

Measure at the longest and widest points, from wall to wall. Don't subtract for closets — they're included in the total square footage.

L-Shaped Room

Divide the L-shape into two rectangles, calculate each, then add them:

1. Measure Rectangle 1: 10 ft × 12 ft = 120 sq ft
2. Measure Rectangle 2: 8 ft × 6 ft = 48 sq ft
3. Total = 120 + 48 = 168 sq ft

Triangle or Diagonal Area

Example: A triangular corner room with base 10 ft and height 8 ft = 0.5 × 10 × 8 = 40 sq ft.

Calculating Total Home Square Footage

To measure an entire home:

1. Measure each room individually (length × width).
2. Include hallways, closets, bathrooms, and laundry rooms.
3. Add all areas together.
4. Exclude garages, unfinished basements, and exterior decks — these are not counted in living space.

How Much Material Do You Need?

Converting Units

• 1 square foot = 144 square inches
• 1 square yard = 9 square feet
• 1 square meter = 10.764 square feet
• 1 acre = 43,560 square feet