How it’s calculated
Square footage is the area of a floor or surface measured in square feet. Measure each room or section, work out its area with the matching formula, then add them up. Split L-shaped rooms into two rectangles.
Example: a 12 ft × 15 ft living room (180 ft²) plus a 10 ft × 10 ft bedroom (100 ft²) totals 280 ft², which is about 26.01 m² or 31.11 yd². At $3.50 per ft² that is $980 of flooring before waste.
| Room size | Square feet |
|---|---|
| 10 ft × 10 ft | 100 ft² |
| 12 ft × 12 ft | 144 ft² |
| 12 ft × 15 ft | 180 ft² |
| 20 ft × 20 ft | 400 ft² |
Frequently asked questions
How do I calculate square footage of a room?
Measure the length and width in feet and multiply them. A 12 ft × 15 ft room is 12 × 15 = 180 square feet.
How do I measure an L-shaped room?
Divide it into two rectangles, measure each one, and enter them as Area 1 and Area 2. The calculator adds them together.
How do I convert inches to square feet?
Pick inches in the unit menu and the calculator converts for you. By hand, multiply length × width in inches and divide by 144, since 1 ft² = 144 in².
How many square feet are in a square meter?
About 10.764 ft². One foot is exactly 0.3048 m, so 1 ft² = 0.09290304 m².
How much extra flooring should I buy?
Typically 5–10% more than the measured area for straight layouts, and 10–15% for diagonal or patterned layouts, to cover cuts and waste.
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Sources
- Prealgebra 2e, 9.4 Use Properties of Rectangles, Triangles, and Trapezoids — OpenStax
- Prealgebra 2e, 9.5 Solve Geometry Applications: Circles and Irregular Figures — OpenStax
- NIST Handbook 44, Appendix C: Units of Measurement — U.S. National Institute of Standards and Technology
Formulas are taken from the free public references above. Results are provided “as is” for informational and educational purposes only. See our disclaimer.
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