Square Footage Calculator
Enter the length and width in your preferred unit to calculate the square footage (and other area units).
Square Footage Guide & Reference
Formula
Area (ft²) = Length (ft) × Width (ft)
For non-rectangular spaces, divide the area into rectangles, calculate each, and sum the results.
Worked example — Rectangular room
Room dimensions: 15 ft × 12 ft
- Area = 15 × 12 = 180 ft²
- In meters: 180 × 0.0929 = 16.72 m²
Worked example — L-shaped room
Split into two rectangles: 10×8 ft and 6×4 ft.
- Rectangle 1 = 10 × 8 = 80 ft²
- Rectangle 2 = 6 × 4 = 24 ft²
- Total = 80 + 24 = 104 ft²
Conversion reference
| From | To | Multiply by |
|---|---|---|
| 1 ft² | in² | 144 |
| 1 ft² | yd² | 0.11111 |
| 1 ft² | m² | 0.09290 |
| 1 m² | ft² | 10.7639 |
| 1 acre | ft² | 43,560 |
| 1 hectare | m² | 10,000 |
Real-world uses
- Flooring & tiling: Calculate material needed + add 10–15% for waste/cuts.
- Painting: 1 gallon typically covers 350–400 ft² per coat.
- Real estate: Property listings use ft² (US) or m² (international).
- HVAC: 1 ton of cooling for every ~500–600 ft² (rule of thumb).
References
- National Association of Realtors (NAR). Square Footage Measurement Guidelines.
- ANSI Z765-2021. Calculating and Reporting Square Footage of Residential Buildings. American National Standards Institute.
- NIST Handbook 44 — Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices.
