Square Miles to Square Kilometers (mi² to km²)
1 square mile equals 2.589988 square kilometers — multiply the number of square miles by 2.589988 to convert. So 5 mi² is 12.94994 km² and 10 mi² is 25.89988 km².
The formula
To convert square miles to square kilometers, multiply by the exact factor:
square kilometers = square miles × 2.589988
For example, 25 mi² × 2.589988 = 64.7497 km². To reverse it, divide square kilometers by 2.589988 (or multiply by 0.38610216).
Conversion table
| Square miles (mi²) | Square kilometers (km²) |
|---|---|
| 1 | 2.589988 |
| 2 | 5.179976 |
| 5 | 12.94994 |
| 10 | 25.89988 |
| 25 | 64.7497 |
| 50 | 129.4994 |
| 100 | 258.9988 |
| 500 | 1,294.994 |
| 1000 | 2,589.988 |
How to convert online
Live and instant:
- Type the number of square miles into the first box.
- Read the square-kilometer value instantly in the second box.
- Or enter a square-kilometer value to convert back — it works both ways.
Use the Square Mile to Square Kilometer Converter — free and instant in your browser.
Where this conversion is used
Square miles are used for US and UK regions, counties and land tracts, while square kilometers are the metric standard worldwide. This conversion is common when comparing the size of cities or countries across sources, or translating imperial survey data into metric for mapping and GIS.
FAQ
How many square kilometers are in a square mile?
One square mile equals 2.589988 square kilometers. Multiply mi² by 2.589988 — 10 mi² = 25.89988 km².
What is the formula to convert square miles to square kilometers?
Square kilometers = mi² × 2.589988. The converter applies this exact factor automatically.
How do I convert square kilometers back to square miles?
Divide by 2.589988, or multiply by 0.38610216. So 1 km² ≈ 0.386 mi².
Is the conversion exact?
It derives from the exact mile-to-kilometer definition; results are precise to the digits shown.
Related converters
- Square Kilometer to Square Mile Converter
- Square Mile to Square Meter Converter
- Square Mile to Acre Converter
- Square Mile to Hectare Converter
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