How to convert square kilometers to square miles
mi² = km² × 0.3861021585Multiply the value in square kilometers by 0.3861021585. To go the other way, multiply by 2.58998811 (or divide by 0.3861021585).
A square kilometer is smaller than a square mile: it takes 2.58998811 square kilometers to make one square mile.
Worked examples
- 1 square kilometer1 km² × 0.3861021585 = 0.3861021585 mi²
- 5 square kilometers5 km² × 0.3861021585 = 1.930510793 mi²
- 10 square kilometers10 km² × 0.3861021585 = 3.861021585 mi²
- 20 square kilometers20 km² × 0.3861021585 = 7.722043171 mi²
- 100 square kilometers100 km² × 0.3861021585 = 38.61021585 mi²
Square kilometers to square miles conversion table
Values are calculated by the conversion engine and rounded to 8 significant figures.
| Square kilometers (km²) | Square miles (mi²) |
|---|---|
| 0.1 km² | 0.038610216 mi² |
| 0.25 km² | 0.09652554 mi² |
| 0.5 km² | 0.19305108 mi² |
| 1 km² | 0.38610216 mi² |
| 2 km² | 0.77220432 mi² |
| 3 km² | 1.1583065 mi² |
| 4 km² | 1.5444086 mi² |
| 5 km² | 1.9305108 mi² |
| 6 km² | 2.316613 mi² |
| 7 km² | 2.7027151 mi² |
| 8 km² | 3.0888173 mi² |
| 9 km² | 3.4749194 mi² |
| 10 km² | 3.8610216 mi² |
| Square kilometers (km²) | Square miles (mi²) |
|---|---|
| 12 km² | 4.6332259 mi² |
| 15 km² | 5.7915324 mi² |
| 20 km² | 7.7220432 mi² |
| 25 km² | 9.652554 mi² |
| 30 km² | 11.583065 mi² |
| 40 km² | 15.444086 mi² |
| 50 km² | 19.305108 mi² |
| 75 km² | 28.957662 mi² |
| 100 km² | 38.610216 mi² |
| 250 km² | 96.52554 mi² |
| 500 km² | 193.05108 mi² |
| 1,000 km² | 386.10216 mi² |
About the units
Square kilometer (km²)
One million square metres or 100 hectares; used for city, lake and country areas. One square kilometer equals 1,000,000 square meters (m²).
Square mile (mi²)
640 acres. Used for US counties, states and wildfire extents. One square mile equals 2,589,988.11 square meters (m²).
Frequently asked questions
How many square miles are in one square kilometer?
There are 0.3861021585 square miles in one square kilometer, and this value is exact by definition.
How do I convert square kilometers to square miles?
Multiply the number of square kilometers by 0.3861021585. For example, 10 km² × 0.3861021585 = 3.861021585 mi².
How many square kilometers are in one square mile?
One square mile equals 2.58998811 square kilometers. That is the reverse factor, 1 ÷ 0.3861021585.
What is 10 square kilometers in square miles?
10 km² = 3.861021585 mi².
Is this km² to mi² converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.