All converters / Area
Square km to square miles
Compare large geographic areas; the length factor is squared.
□ Area Instant conversion
Edit either value. Use a decimal point; commas group thousands. Rounding affects display only.
How to convert square kilometers to square miles
Compare large geographic areas; the length factor is squared.
mi² = km² × 0.3861021585
Formula coefficients shown rounded. Calculations use the stored factors before display rounding.
A worked example
For 10 km², the result is approximately 3.861021585 mi². To go the other way, edit the result above or swap the units.
Know your units
Square units scale in two dimensions: one square meter equals 10,000 square centimeters.
Where the numbers come from
Factors follow NIST conversion references and documented unit definitions. Read our accuracy and rounding notes.
The table and method describe this page’s original pair. Changing units above does not change this reference section.
| Square kilometers (km²) | Square miles (mi²) |
|---|---|
| 1 | 0.3861021585 |
| 2 | 0.7722043171 |
| 5 | 1.930510793 |
| 10 | 3.861021585 |
| 20 | 7.722043171 |
| 25 | 9.652553964 |
| 50 | 19.30510793 |
| 100 | 38.61021585 |
| 500 | 193.0510793 |
| 1000 | 386.1021585 |