How to convert square miles to square kilometres
km² = mi² × 2.58998811
Example: 5 mi² × 2.58998811 = 12.94994055 km²
Square Miles to Square Kilometers table
| Square Miles (mi²) | Square Kilometers (km²) |
|---|---|
| 0.5 mi² | 1.2949941 km² |
| 1 mi² | 2.5899881 km² |
| 2 mi² | 5.1799762 km² |
| 3 mi² | 7.7699643 km² |
| 4 mi² | 10.359952 km² |
| 5 mi² | 12.949941 km² |
| 6 mi² | 15.539929 km² |
| 7 mi² | 18.129917 km² |
| 8 mi² | 20.719905 km² |
| 9 mi² | 23.309893 km² |
| 10 mi² | 25.899881 km² |
| 15 mi² | 38.849822 km² |
| 20 mi² | 51.799762 km² |
| 25 mi² | 64.749703 km² |
| 30 mi² | 77.699643 km² |
| 40 mi² | 103.59952 km² |
| 50 mi² | 129.49941 km² |
| 75 mi² | 194.24911 km² |
| 100 mi² | 258.99881 km² |
| 250 mi² | 647.49703 km² |
| 500 mi² | 1,294.9941 km² |
| 1,000 mi² | 2,589.9881 km² |
About these units
Square Miles (mi²): A square mile is 640 acres, about 2.59 km². It is used for large land areas in the US and UK.
Square Kilometers (km²): A square kilometre is 1,000,000 m² or 100 hectares, used for the area of cities, lakes and countries.
Frequently asked questions
How many square kilometres are in 1 square mile?
1 square mile (mi²) equals 2.58998811 square kilometres (km²).
How do I convert mi² to km²?
Multiply the value in square miles by 2.58998811. For example, 5 mi² × 2.58998811 = 12.94994055 km².
How do I convert square kilometres back to square miles?
Multiply by 0.3861021585 (or divide by 2.58998811). 1 km² = 0.3861021585 mi².
What is a square mile?
A square mile is 640 acres, about 2.59 km². It is used for large land areas in the US and UK.
Conversion factors come from exact international definitions (NIST SP 811, BIPM) where they exist. Results show up to 10 significant digits. Need every area unit at once? Use the Area Converter.