Square footage is the area of a space measured in square feet (ft²). It is the standard unit for rooms, apartments, and property listings in the United States. In metric countries the equivalent is square metres (m²). Knowing how to measure accurately saves money on flooring, paint, and materials.
What Is Square Footage?
Square footage simply means the area expressed in feet squared. A room that is 12 feet long and 10 feet wide has 120 square feet (12 × 10 = 120 ft²). The concept applies equally to any rectangular space.
For metric: Area (m²) = Length (m) × Width (m)
Conversion: 1 m² = 10.764 ft² | 1 ft² = 0.0929 m²
How to Measure a Room Step by Step
- Clear the room — move furniture away from walls for accurate measurements.
- Measure the length — run your tape measure along the longest wall from corner to corner.
- Measure the width — measure the perpendicular wall in the same way.
- Multiply — Length × Width = square footage.
- Record units — make sure both measurements use the same unit (feet or metres).
Use the Square Footage Calculator to get instant results after measuring.
Handling Irregular Rooms
Not all rooms are simple rectangles. Here are strategies for common irregular shapes:
L-Shaped Rooms
Divide the L into two rectangles. Measure each rectangle separately, then add the two areas together.
Example: Main section 15 × 12 = 180 ft² + Alcove 8 × 6 = 48 ft²
Total = 228 ft²
Rooms with Closets
Measure the main room and the closet separately, then add them. For real estate listings, walk-in closets are typically included in the total square footage.
Rooms with Angled Walls
Break the space into a rectangle plus a triangle. Calculate each area using the Rectangle Calculator and Triangle Calculator, then add them.
Converting Between m² and ft²
| From | To | Multiply by |
|---|---|---|
| ft² | m² | 0.0929 |
| m² | ft² | 10.764 |
| ft² | yd² | 0.1111 |
| m² | acres | 0.000247 |
Real-World Applications
Flooring
Add 10% waste factor: if the room is 200 ft², buy 220 ft² of material. For diagonal installations, add 15%.
Paint Coverage
One gallon of paint covers approximately 350–400 ft² (32–37 m²). Measure wall area (perimeter × height) minus windows and doors. See our painting rooms guide for detailed wall calculations.
Real Estate
Property values are often quoted per square foot. If a home is listed at $300/ft² and measures 1,500 ft², the asking price is $450,000.
Quick Reference: Common Room Sizes
| Room | Typical Size (ft²) | Typical Size (m²) |
|---|---|---|
| Small bedroom | 100–120 | 9–11 |
| Master bedroom | 200–300 | 19–28 |
| Living room | 200–400 | 19–37 |
| Kitchen | 100–200 | 9–19 |
| Bathroom | 40–100 | 4–9 |
| Single garage | 200–250 | 19–23 |
Related Calculators and Articles
Use the Square Footage Calculator for quick room measurements. For other area calculations, try the Rectangle Area Calculator, Triangle Area Calculator, or the general Area Calculator.
For 3D space calculations, see Rectangular Prism Volume. Also read How to Calculate Area and Area Formulas Cheat Sheet.