How to convert square miles to square kilometers
To convert square miles to square kilometers, multiply by 2.58998811034. Area conversions are essential for real estate, flooring, land surveys, farming and map reading.
Square Mile to Square Kilometer conversion table
| Square Mile (mi²) | Square Kilometer (km²) |
|---|---|
| 0.1 mi² | 0.258998811034 km² |
| 0.5 mi² | 1.29499405517 km² |
| 1 mi² | 2.58998811034 km² |
| 2 mi² | 5.17997622067 km² |
| 3 mi² | 7.76996433101 km² |
| 4 mi² | 10.3599524413 km² |
| 5 mi² | 12.9499405517 km² |
| 10 mi² | 25.8998811034 km² |
| 20 mi² | 51.7997622067 km² |
| 25 mi² | 64.7497027584 km² |
| 50 mi² | 129.499405517 km² |
| 100 mi² | 258.998811034 km² |
| 500 mi² | 1,294.99405517 km² |
| 1,000 mi² | 2,589.98811034 km² |
About the units
Square Mile (mi²)
A square mile equals 640 acres, or about 2.59 square kilometers.
Square Kilometer (km²)
A square kilometer equals 1,000,000 m² and measures cities, lakes and countries.
How to use this converter
- Type the number of square miles (mi²) in the input box.
- The result in square kilometers appears instantly — no button needed.
- See the same value in every other area unit just below.
- Use “Swap units” to convert square kilometers back to square miles.
Tips for better results
- Double-check which system a unit belongs to (for example US vs UK gallons).
- Use the swap button to convert in the opposite direction instantly.
- Bookmark the conversions you use most — each pair has its own page.
Frequently asked questions
How many square kilometers are in one square mile?
One square mile equals 2.58998811034 square kilometers. 2.58998811034 is the exact factor used by this converter.
How do I convert square miles to square kilometers?
Multiply the value in square miles by 2.58998811034. To go the other way, multiply square kilometers by 0.386102158542.
What is 10 mi² in km²?
10 mi² = 25.8998811034 km². Also, 5 mi² = 12.9499405517 km² and 100 mi² = 258.998811034 km².
What is the difference between a square mile and a square kilometer?
A square mile equals 640 acres, or about 2.59 square kilometers. A square kilometer equals 1,000,000 m² and measures cities, lakes and countries.
Is this tool free and private?
Yes — the Square Mile to Square Kilometer is completely free with no sign-up, and it runs entirely in your browser, so the values you enter are never uploaded to our servers.
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