Area units get mixed constantly: flooring is sold by the square foot, European product sheets use square metres, land is measured in acres or hectares, and sod is often priced by the square yard. This area converter converts between nine units using the exact definitions behind them. Since 1959 the international foot has been exactly 0.3048 metre, so one square foot is exactly 0.09290304 square metre. The converter shows the conversion step and a table of the area in every unit at once.
To measure a room or yard in the first place, use the square footage calculator; for volumes, use the cubic feet calculator.
How to use the area converter
- Enter the area.
- Choose the unit you have and the unit you want.
- Read the converted value, or scan the table for every unit.
- Keep full precision for further calculations and round only the final figure.
Formula
Area factors are the squares of the length factors: 1 yd = 3 ft, so 1 yd² = 9 ft²; 1 ft = 12 in, so 1 ft² = 144 in².
Worked example
1,500 ft² to m²: 1,500 × 0.09290304 = 139.3546 m².
2.5 acres to hectares: 2.5 × 4,046.8564224 = 10,117.14 m², and ÷ 10,000 = 1.0117 ha.
45 m² to ft²: 45 ÷ 0.09290304 = 484.376 ft².
Area conversion table
| 1 unit | Square feet | Square metres |
|---|---|---|
| Square inch | 0.006944 | 0.00064516 |
| Square foot | 1 | 0.09290304 |
| Square yard | 9 | 0.83612736 |
| Acre | 43,560 | 4,046.856 |
| Square mile | 27,878,400 | 2,589,988 |
| Square metre | 10.76391 | 1 |
| Hectare | 107,639.1 | 10,000 |
| Square kilometre | 10,763,910 | 1,000,000 |
International acre vs US survey acre
Until the end of 2022, some US land surveys used the US survey foot (1200/3937 m), which is about 2 parts per million longer than the international foot. NIST and NOAA retired the survey foot for new work from 1 January 2023, but older deeds and plats may still use survey acres. The difference is about 0.016 m² per acre, which is negligible for home projects but can matter in legal descriptions of large parcels. This converter uses the international definitions.
Converting area is not the same as converting length. Doubling every side of a square multiplies its area by four, so don't scale a length conversion factor linearly when working with areas.
Converting room measurements with feet and inches
Room sizes are often written in feet and inches, such as 12 ft 6 in × 10 ft 3 in. Convert each side to decimal feet first by dividing the inches by 12: 12.5 ft × 10.25 ft = 128.125 ft². Then convert the area: 128.125 × 0.09290304 = 11.90 m². Don't multiply 12.6 by 10.3, because 6 inches is half a foot, not 0.6 of one. Handy whole-number relationships: 144 in² = 1 ft², 9 ft² = 1 yd², 43,560 ft² = 1 acre, 640 acres = 1 square mile, and 10,000 m² = 1 hectare. For irregular rooms, the square footage calculator adds up rectangles and triangles before you convert.
Caveats and assumptions
- Uses international foot-based definitions (1 ft = 0.3048 m exactly). Historical US survey acres differ by about 4 parts per million.
- Displayed values are rounded to about ten significant figures.
- Retail products are often labelled in rounded units; a "1 m²" pack may cover 10.76 ft² or be listed as 10.8 ft².
- Negative areas are rejected.
Frequently asked questions
How do I convert square feet to square meters?
Multiply by 0.09290304. For example, 200 ft² × 0.09290304 = 18.58 m².
How do I convert square meters to square feet?
Divide by 0.09290304, or multiply by about 10.7639. 50 m² ≈ 538.2 ft².
How many square feet are in an acre?
Exactly 43,560 square feet, which is about 4,046.86 square metres.
How many acres are in a hectare?
About 2.4711 acres. One hectare is 10,000 square metres.
How many square feet are in a square yard?
Nine, because a yard is 3 feet and 3 × 3 = 9.
Sources
- NIST — SP 811 Appendix B.8, Factors for Units Listed Alphabetically — exact area conversion factors
- NIST Office of Weights and Measures — Unit Conversion — US customary to metric conversions
- NIST Handbook 44 — Specifications, Tolerances, and Other Technical Requirements — Appendix C, units and tables
This calculator gives estimates for planning and education. Check measurements, local codes, supplier specs and your school's official policy before relying on a result. See our disclaimer and how we build and check calculators.