km² to square miles Converter
1 km² = 0.3861 mi². Enter a value. The result updates immediately.
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Accuracy and rounding
Useful for rooms, land, materials, and drawings. Area conversions square the length factor, so they are not the same as length conversions.
Area units are derived from fixed length definitions. The factor is squared, so area conversions are not the same as length conversions.
For rooms and land, round after multiplying by quantity or price. Small rounding errors can grow on large areas.
How to convert km² to square miles
- Enter the value in km².
- Select km² as the source unit.
- Select square miles as the target unit.
- Read or copy the result.
km² to square miles chart
| km² | square miles |
|---|---|
| 1 km² | 0.3861 mi² |
| 2 km² | 0.7722 mi² |
| 5 km² | 1.9305 mi² |
| 10 km² | 3.861 mi² |
| 25 km² | 9.6526 mi² |
| 50 km² | 19.3051 mi² |
| 100 km² | 38.6102 mi² |
Formula
mi² = km² x 0.386102158542
Example: 1 km² = 0.3861 mi².
Source
Area units derived from exact length definitions; acre and hectare factors are fixed.
Common questions
How do I convert km² to square miles?
Enter the km² value in the converter, or multiply by the factor shown in the formula. 1 km² = 0.3861 mi².
What should I watch out for?
Area conversions square the length relationship, so they are different from plain length conversions.
Where does this area conversion come from?
Area units derived from exact length definitions; acre and hectare factors are fixed. ConverterBase uses stable definitions and fixed conversion factors, not live or rounded market data.