Square Miles to Square Kilometers Converter
Convert square miles to square kilometers instantly. Type a value, change either unit, or press swap to go the other way. 1 square mile = 2.5899881 square kilometers.
1 square mile = 2.5899881 square kilometers
How to convert square miles to square kilometers
square kilometers = square miles × 2.58998811
To convert square miles to square kilometers, multiply the value by 2.58998811. To go back from square kilometers to square miles, divide by the same number (or multiply by 0.3861021585).
Worked examples
- 10 mi²: 10 × 2.58998811 = 25.899881 km²
- 50 mi²: 50 × 2.58998811 = 129.49941 km²
- 100 mi²: 100 × 2.58998811 = 258.99881 km²
Multiply square miles by 2.6 for a fast estimate. A 100 square mile area is about 259 square kilometers.
Square Miles to Square Kilometers conversion table
Square Miles to Square Kilometers
| mi² | km² |
|---|---|
| 1 | 2.5899881 |
| 5 | 12.949941 |
| 10 | 25.899881 |
| 50 | 129.49941 |
| 100 | 258.99881 |
| 500 | 1,294.9941 |
| 1,000 | 2,589.9881 |
| 5,000 | 12,949.941 |
| 10,000 | 25,899.881 |
| 100,000 | 258,998.81 |
Square Kilometers to Square Miles
| km² | mi² |
|---|---|
| 1 | 0.38610216 |
| 5 | 1.9305108 |
| 10 | 3.8610216 |
| 50 | 19.305108 |
| 100 | 38.610216 |
| 500 | 193.05108 |
| 1,000 | 386.10216 |
| 5,000 | 1,930.5108 |
| 10,000 | 3,861.0216 |
| 100,000 | 38,610.216 |
Area equivalents
See how one square mile and one square kilometer compare with every other area unit on the site.
1 square mile equals
| Unit | Value |
|---|---|
| square inches (in²) | 4,014,489,600 |
| square centimeters (cm²) | 25,899,881,103 |
| square feet (ft²) | 27,878,400 |
| square yards (yd²) | 3,097,600 |
| square meters (m²) | 2,589,988 |
| acres (ac) | 640 |
| hectares (ha) | 258.9988 |
| square kilometers (km²) | 2.589988 |
1 square kilometer equals
| Unit | Value |
|---|---|
| square inches (in²) | 1,550,003,100 |
| square centimeters (cm²) | 10,000,000,000 |
| square feet (ft²) | 10,763,910 |
| square yards (yd²) | 1,195,990 |
| square meters (m²) | 1,000,000 |
| acres (ac) | 247.1054 |
| hectares (ha) | 100 |
| square miles (mi²) | 0.3861022 |
When you need to convert square miles to square kilometers
The size of cities, national parks, lakes and countries is often given in square miles in American and British sources, and in square kilometers everywhere else. A reliable converter makes it easy to compare geography, from the area of a state to the size of a wildfire.
About the units
Square mile (mi²)
A square mile is 640 acres, or about 2.59 square kilometers. It is used for the area of cities, states and counties in the US and UK.
Square kilometer (km²)
A square kilometer is one million square meters. It is used for the area of cities, parks and countries.
Frequently asked questions
How do I convert square miles to square kilometers?
Multiply the number of square miles by 2.58998811. For example, 10 square miles × 2.58998811 = 25.8998811 square kilometers.
How many square kilometers are in one square mile?
There are 2.58998811 square kilometers in one square mile.
How many square miles are in one square kilometer?
There are 0.3861021585 square miles in one square kilometer.
How many acres are in a square mile?
There are exactly 640 acres in one square mile. One square mile is also about 2.59 square kilometers, or 258.999 hectares.
Can I convert other area units with this tool?
Yes. Use the From and To drop-downs in the converter to choose any area unit, or press the swap button to reverse the conversion. All calculations use internationally defined conversion factors.