Square Mile to Square Kilometre
Free instant square mile to square kilometre converter. 1 mi² = 2.58999 km².
Common Square Mile to Square Kilometre values
| Square Mile (mi²) | Square Kilometre (km²) |
|---|---|
| 1 | 2.58999 |
| 5 | 12.9499 |
| 10 | 25.8999 |
| 25 | 64.7497 |
| 50 | 129.499 |
| 100 | 258.999 |
| 500 | 1294.99 |
| 1000 | 2589.99 |
How does Square Mile to Square Kilometre conversion work?
Type a value in the Square Mile (mi²) field and the equivalent in Square Kilometre (km²) appears instantly to the right. The math uses the exact formula shown above — no rounding errors, no approximations beyond standard floating-point precision. Use the swap button to flip the units and see the inverse conversion.
Square Mile. A square one mile on each side. About 2.59 square kilometres or 640 acres.
Square Kilometre. A square one kilometre on each side. Equal to 100 hectares or about 247 acres.
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🎯 Accurate conversions
Conversion factors come from the official standard (NIST, BIPM, ISO definitions where applicable). Values are precise to standard floating-point limits.
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