1 square mile = 2.58998811 square kilometres
A square mile is 2.58999 km². Because area scales as the square, the 1.6 factor between miles and kilometres becomes 2.59 here, which is why city areas look so different in the two units.
Formula km² = mi² × 2.589988110336
Type in either field — the other updates on every keystroke. Need other units? Open the full area converter.
| Square mile | Square kilometre |
|---|---|
| 1 mi² | 2.589988 km² |
| 2 mi² | 5.179976 km² |
| 3 mi² | 7.769964 km² |
| 4 mi² | 10.359952 km² |
| 5 mi² | 12.949941 km² |
| 10 mi² | 25.899881 km² |
| 15 mi² | 38.849822 km² |
| 20 mi² | 51.799762 km² |
| 25 mi² | 64.749703 km² |
| 50 mi² | 129.499406 km² |
| 100 mi² | 258.998811 km² |
| 500 mi² | 1294.994055 km² |
| 1000 mi² | 2589.98811 km² |
| Square kilometre | Square mile |
|---|---|
| 1 km² | 0.386102 mi² |
| 2 km² | 0.772204 mi² |
| 3 km² | 1.158306 mi² |
| 4 km² | 1.544409 mi² |
| 5 km² | 1.930511 mi² |
| 10 km² | 3.861022 mi² |
| 15 km² | 5.791532 mi² |
| 20 km² | 7.722043 mi² |
| 25 km² | 9.652554 mi² |
| 50 km² | 19.305108 mi² |
| 100 km² | 38.610216 mi² |
| 500 km² | 193.051079 mi² |
| 1000 km² | 386.102159 mi² |
| Situation | From | To |
|---|---|---|
| One square mile | 1 mi² | 2.59 km² |
| Manhattan | 22.8 mi² | 59.05 km² |
| Washington, D.C. | 68.3 mi² | 176.9 km² |
| Greater London | 607 mi² | 1,572 km² |
| Rhode Island | 1,545 mi² | 4,002 km² |
| Texas | 268,596 mi² | 695,660 km² |
Multiply by 2.6. 10 mi² is about 26 km², against an exact 25.9.
Land areas of cities, parks and states are given in square miles in the US and square kilometres elsewhere. Greater London covers 607 mi², or about 1,572 km².
A "3-mile square" is 9 square miles, but "3 square miles" is not a 3 by 3 square. Square the side before you convert.
A square mile is 640 acres or 2.589988 km². US land survey sections are one square mile each.
One square mile is 2.59 km² and contains 640 acres.
Related guides: Imperial vs metric: differences and quick conversion tricks