Square miles to Square kilometers formula
square kilometers = square miles × 2.58999
Multiply the number of square miles by 2.58999 to get square kilometers. To go the other way, multiply by 0.386102 instead, or use the square km to square miles converter.
Square miles to Square kilometers conversion table
Common square miles to square km values, rounded for reading. The converter above keeps full precision.
| Square miles | Square kilometers |
|---|---|
| 1 mi² | 2.58999 km² |
| 2 mi² | 5.17998 km² |
| 3 mi² | 7.76996 km² |
| 4 mi² | 10.36 km² |
| 5 mi² | 12.9499 km² |
| 10 mi² | 25.8999 km² |
| 15 mi² | 38.8498 km² |
| 20 mi² | 51.7998 km² |
| 25 mi² | 64.7497 km² |
| 50 mi² | 129.499 km² |
| 75 mi² | 194.249 km² |
| 100 mi² | 258.999 km² |
| 250 mi² | 647.497 km² |
| 500 mi² | 1,294.99 km² |
| 1,000 mi² | 2,589.99 km² |
Worked example
To convert 10 mi² to square kilometers, multiply by 2.58999: the result is 25.8999 km². Area conversion factors are squared length factors. One acre equals exactly 4,046.8564224 square meters.
Frequently asked questions
How many square kilometers are in a square mile?
One square mile equals 2.58999 square kilometers (1 mi² = 2.58999 km²).
What is 10 square miles in square kilometers?
10 mi² converts to 25.8999 km². Enter any other value in the converter above to see it recalculated instantly.
How do I convert square kilometers back to square miles?
Reverse the calculation: one square kilometer equals 0.386102 square miles. You can also swap the units in the converter or open the square km to square miles page.
Related area conversions
Need a different pair? Open the full area converter to choose any two units.