Convert Square Kilometres to Square Miles (km2 to mi2)
1 square kilometre (km²) = 0.3861021585 square miles (mi²). 1 mi² = 2.58998811 km². Example: 15 km² = 15 × 0.3861021585 = 5.791532378 mi².
Also searched as square kilometres to mi2, square kilometres in mi2, square kilometres into square miles, km2 to mi2, km2 in square miles, km2 into square mile, square kilometre to square mile, km2 to square miles converter, square kilometers to square miles and how many square miles in a square kilometre.
1 km² = 0.3861021585 mi²
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk square kilometre to square mile converter to paste a column from Excel.
How to Convert Square Kilometre to Square Mile
- 1 km² = 0.3861021585 mi²
- 1 mi² = 2.58998811 km²
- Example: convert 15 km² to mi²: 15 km² = 15 × 0.3861021585 mi² = 5.791532378 mi²
Formula
mi² = km² × 0.3861021585424
or mi² = km² ÷ 2.589988110336
Derivation from SI units:
- 1 km² = (1000 m)² = 10⁶ m² = 100 ha
- 1 mi² = (1609.344 m)² = 2 589 988.110336 m² = 640 acres
- 1 km² = 1000000 m² ÷ 2589988.110336 m² per mi² = 0.3861021585424 mi²
Both units are defined exactly, so the factor is exact. Square Kilometre definition: square kilometre; Square Mile definition: square mile.
Worked examples
- A reading of 2 km² converts to 0.7722043171 mi².
2 km² × 0.3861021585 = 0.7722043171 mi² - A value of 50 km² is 19.30510793 mi².
50 km² × 0.3861021585 = 19.30510793 mi²
Square Kilometre to Square Mile conversion table
| Square Kilometres (km²) | Square Miles (mi²) |
|---|---|
| 0.01 km² | 0.003861021585 mi² |
| 0.1 km² | 0.03861021585 mi² |
| 0.5 km² | 0.1930510793 mi² |
| 1 km² | 0.3861021585 mi² |
| 2 km² | 0.7722043171 mi² |
| 5 km² | 1.930510793 mi² |
| 10 km² | 3.861021585 mi² |
| 25 km² | 9.652553964 mi² |
| 50 km² | 19.30510793 mi² |
| 100 km² | 38.61021585 mi² |
| 1000 km² | 386.1021585 mi² |
| 10000 km² | 3861.021585 mi² |
Where it's used
Square Kilometres are used for city, lake and country areas, while square miles appear in US city and county areas. Both measure area, so the conversion is a fixed factor.
Square Kilometre to other area units
| Conversion | 1 km² equals |
|---|---|
| square kilometre to square mile | 0.3861021585 mi² |
| square kilometre to square meter | 1000000 m² |
| square kilometre to square centimeter | 10000000000 cm² |
| square kilometre to square foot | 10763910.42 ft² |
| square kilometre to square inch | 1550003100 in² |
| square kilometre to hectare | 100 ha |
| square kilometre to acre | 247.1053815 ac |
| square kilometre to square millimeter | 1000000000000 mm² |
Show 1 more units
| square kilometre to square yard | 1195990.046 yd² |
|---|
Frequently asked questions
How many square miles are in 1 square kilometre?
1 km² = 0.3861021585 mi².
How do I convert square kilometres to square miles?
Multiply the value in km² by 0.3861021585, or divide it by 2.58998811. For example, 15 km² × 0.3861021585 = 5.791532378 mi².
Is the km² 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 7, SI prefixes.
- 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 Square Kilometres to Square Miles (km2 to mi2). Retrieved October 25, 2026, from https://scientificconverters.com/area/square-kilometers-to-square-miles/
IEEE
Scientific Converters, "Convert Square Kilometres to Square Miles (km2 to mi2)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/area/square-kilometers-to-square-miles/