Choose source and target units. Every conversion passes through square meters using defined length relationships squared. For a small surface already measured in cm² or mm², use the square centimeters to square millimeters converter. Those units are not in this menu; the focused converter works in both directions and applies the squared factor of 100.
Factors in square meters
| Unit | Exact dimensional factor |
|---|---|
| square inch | 0.0254² |
| square foot | 0.3048² = 0.09290304 |
| square yard | (3 × 0.3048)² = 0.83612736 |
| square mile | (5,280 × 0.3048)² = 2,589,988.110336 |
| acre | 43,560 × 0.3048² = 4,046.8564224 |
| hectare | 10,000 |
| square kilometer | 1,000,000 |
For example, 850 ft² is 850 × 0.09290304 = 78.967584 m². Results are rounded only after conversion. Negative areas, unknown units, invalid numeric inputs, and conversions with results too large to represent are rejected.
For related area conversions, use the acres to square feet converter, the square feet to square meters calculator, or the hectares to acres converter.
Reconcile an area specification
Convert the entire area value into the unit requested by the specification, keeping the original area unit in your notes. If you also have boundary lengths, do not substitute one of those lengths into the area field. A useful final check is whether both figures describe the same surface rather than merely the same project.
Sources
- NIST, Guide for the Use of the International System of Units (SP 811) — SI units and accepted conversion guidance.
- NIST, Handbook 44, Appendix C — U.S. customary volume and length relationships used for dimensional arithmetic.