Square Miles to Square Kilometers (mi² to km²)
Free online square mile to square kilometer converter. Type a value, get an instant exact result — plus the formula, a ready-made conversion table, and reverse conversion.
AREA CONVERTER — INSTANT RESULT
Formula: multiply the square mile value by 2.58998811 — i.e. km² = mi² × 2.58998811
Quick check: 1 mi² = 2.58998811 km²
Quick check: 1 mi² = 2.58998811 km²
Square Miles to Square Kilometers conversion table
| Square Miles (mi²) | Square Kilometers (km²) |
|---|---|
| 1 mi² | 2.58998811 km² |
| 2 mi² | 5.17997622 km² |
| 3 mi² | 7.76996433 km² |
| 4 mi² | 10.35995244 km² |
| 5 mi² | 12.94994055 km² |
| 6 mi² | 15.53992866 km² |
| 7 mi² | 18.12991677 km² |
| 8 mi² | 20.71990488 km² |
| 9 mi² | 23.30989299 km² |
| 10 mi² | 25.8998811 km² |
| 15 mi² | 38.84982166 km² |
| 20 mi² | 51.79976221 km² |
| 25 mi² | 64.74970276 km² |
| 30 mi² | 77.69964331 km² |
| 40 mi² | 103.59952441 km² |
| 50 mi² | 129.49940552 km² |
| 75 mi² | 194.24910828 km² |
| 100 mi² | 258.99881103 km² |
| 250 mi² | 647.49702758 km² |
| 500 mi² | 1,294.99405517 km² |
| 1,000 mi² | 2,589.98811034 km² |
How to convert square miles to square kilometers
To convert square miles to square kilometers, multiply the amount in square miles by 2.58998811. For example, 10 mi² = 25.8998811 km². To convert in the other direction, divide by the same factor, or use the ⇄ swap button above.
Convert between metric and imperial/US land area units, including the acre (43,560 ft² exactly) and hectare (10,000 m²) used worldwide for land measurement.
Frequently asked questions
How many square kilometers are in one square mile?
One square mile is exactly 2.58998811 square kilometers.
How do I convert mi² to km²?
Multiply the mi² value by 2.58998811 to get km². The converter at the top of this page does this automatically and works in both directions.
How much is 100 square miles in square kilometers?
100 square miles equals 258.99881103 square kilometers.