Square miles to Square kilometres Converter
Enter square miles to get square kilometres instantly. Works both ways.
How to convert square miles to square km
To convert square miles to square kilometres, multiply by 2.58999. For example, 5 square miles × 2.58999 = 12.9499 square km.
Need it the other way? Convert square kilometres to square miles.
Square miles to Square kilometres at a glance
- 1 square mile = 2.589988 square kilometres
- 5 square miles = 12.94994 square kilometres
- 10 square miles = 25.89988 square kilometres
- 50 square miles = 129.4994 square kilometres
- 100 square miles = 258.9988 square kilometres
- 1 square kilometre = 0.3861022 square miles (the reverse)
Worked examples
25 square miles × 2.589988 = 64.7497 square kilometres.
250 square miles × 2.589988 = 647.497 square kilometres.
1,500 square miles × 2.589988 = 3,884.982 square kilometres.
Converting back
To go from square kilometres back to square miles, divide by 2.589988 (or multiply by 0.3861022). For example, 100 square kilometres ÷ 2.589988 = 38.61022 square miles.
Using a rounded factor
For a quick estimate you can use 2.6 in place of 2.589988. That is accurate to within about 0.4%, which is fine for rough checks but not for exact work.
Square miles to square km chart
| Square miles | Square kilometres |
|---|---|
| 0.1 square miles | 0.258999 square km |
| 0.25 square miles | 0.647497 square km |
| 0.5 square miles | 1.29499 square km |
| 1 square miles | 2.58999 square km |
| 2 square miles | 5.17998 square km |
| 3 square miles | 7.76996 square km |
| 4 square miles | 10.36 square km |
| 5 square miles | 12.9499 square km |
| 6 square miles | 15.5399 square km |
| 7 square miles | 18.1299 square km |
| 8 square miles | 20.7199 square km |
| 9 square miles | 23.3099 square km |
| 10 square miles | 25.8999 square km |
| 15 square miles | 38.8498 square km |
| 20 square miles | 51.7998 square km |
| 25 square miles | 64.7497 square km |
| 30 square miles | 77.6996 square km |
| 40 square miles | 103.6 square km |
| 50 square miles | 129.499 square km |
| 75 square miles | 194.249 square km |
| 100 square miles | 258.999 square km |
| 250 square miles | 647.497 square km |
| 500 square miles | 1,294.99 square km |
| 1,000 square miles | 2,589.99 square km |
More area & land conversions
Frequently asked questions
How many square kilometres are in one square mile?
There are 2.58999 square kilometres in one square mile.
How do I convert square miles to square km?
Multiply the value in square miles by 2.58999.
How many square miles are in one square kilometre?
There are 0.3861022 square miles in one square kilometre.
What is 10 square miles in square kilometres?
10 square miles = 25.89988 square kilometres.
How do I convert square kilometres back to square miles?
Divide the value in square kilometres by 2.589988, or multiply it by 0.3861022.
Can I use a rounded factor for square miles to square kilometres?
For quick estimates, 2.6 is close (within about 0.4%). Use 2.589988 when you need the full figure.