Convert Hectares to Square Miles (ha to mi2)
1 hectare (ha) = 0.003861021585 square miles (mi²). 1 mi² = 258.998811 ha. Example: 15 ha = 15 × 0.003861021585 = 0.05791532378 mi².
Also searched as hectares to mi2, hectares in mi2, hectares into square miles, ha to mi2, ha in square miles, ha into square mile, hectare to square mile, ha to square miles converter and how many square miles in a hectare.
1 ha = 0.003861021585 mi²
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk hectare to square mile converter to paste a column from Excel.
How to Convert Hectare to Square Mile
- 1 ha = 0.003861021585 mi²
- 1 mi² = 258.998811 ha
- Example: convert 15 ha to mi²: 15 ha = 15 × 0.003861021585 mi² = 0.05791532378 mi²
Formula
mi² = ha × 0.003861021585424
or mi² = ha ÷ 258.9988110336
Derivation from SI units:
- 1 ha = 100 m × 100 m = 10 000 m² (a non-SI unit accepted for use with the SI)
- 1 mi² = (1609.344 m)² = 2 589 988.110336 m² = 640 acres
- 1 ha = 10000 m² ÷ 2589988.110336 m² per mi² = 0.003861021585424 mi²
Both units are defined exactly, so the factor is exact. Hectare definition: hectare; Square Mile definition: square mile.
Worked examples
- A reading of 1 ha converts to 0.003861021585 mi².
1 ha × 0.003861021585 = 0.003861021585 mi² - A value of 20 ha is 0.07722043171 mi².
20 ha × 0.003861021585 = 0.07722043171 mi²
Hectare to Square Mile conversion table
| Hectares (ha) | Square Miles (mi²) |
|---|---|
| 0.01 ha | 0.00003861021585 mi² |
| 0.1 ha | 0.0003861021585 mi² |
| 0.25 ha | 0.0009652553964 mi² |
| 0.5 ha | 0.001930510793 mi² |
| 1 ha | 0.003861021585 mi² |
| 2 ha | 0.007722043171 mi² |
| 2.5 ha | 0.009652553964 mi² |
| 5 ha | 0.01930510793 mi² |
| 10 ha | 0.03861021585 mi² |
| 20 ha | 0.07722043171 mi² |
| 40.4686 ha | 0.1562501381 mi² |
| 50 ha | 0.1930510793 mi² |
| 100 ha | 0.3861021585 mi² |
| 1000 ha | 3.861021585 mi² |
Where it's used
Hectares are used for farm and forest land, while square miles appear in US city and county areas. Both measure area, so the conversion is a fixed factor.
Hectare to other area units
| Conversion | 1 ha equals |
|---|---|
| hectare to square mile | 0.003861021585 mi² |
| hectare to square meter | 10000 m² |
| hectare to square centimeter | 100000000 cm² |
| hectare to square foot | 107639.1042 ft² |
| hectare to square inch | 15500031 in² |
| hectare to acre | 2.471053815 ac |
| hectare to square millimeter | 10000000000 mm² |
| hectare to square kilometre | 0.01 km² |
Show 1 more units
| hectare to square yard | 11959.90046 yd² |
|---|
Frequently asked questions
How many square miles are in 1 hectare?
1 ha = 0.003861021585 mi².
How do I convert hectares to square miles?
Multiply the value in ha by 0.003861021585, or divide it by 258.998811. For example, 15 ha × 0.003861021585 = 0.05791532378 mi².
Is the ha to mi² conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 8, non-SI units accepted for use with the SI.
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "square mile (mi²)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Hectares to Square Miles (ha to mi2). Retrieved October 25, 2026, from https://scientificconverters.com/area/hectares-to-square-miles/
IEEE
Scientific Converters, "Convert Hectares to Square Miles (ha to mi2)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/area/hectares-to-square-miles/