Convert Square miles to square kilometers

1 square mile = 2.59 square kilometers · km² = mi² × 2.58998811

mi²
Square kilometers
2.59km²

1 square mile = 2.59 square kilometers

When you need this conversion

This conversion goes from square miles, used for US counties, states, and large regions, to square kilometers, used for cities, parks, and regions. Both measure the same physical quantity, so the conversion is exact — the difference is which unit your source, tool, or region happens to use.

Square miles to square kilometers conversion table

Conversion table from square miles to square kilometers
Square miles (mi²)Square kilometers (km²)
1 mi²2.59 km²
2 mi²5.18 km²
3 mi²7.77 km²
5 mi²12.9499 km²
10 mi²25.8999 km²
15 mi²38.8498 km²
20 mi²51.7998 km²
25 mi²64.7497 km²
50 mi²129.5 km²
75 mi²194.25 km²
100 mi²259 km²
250 mi²647.5 km²
500 mi²1,294.99 km²
1,000 mi²2,589.99 km²

The formula

km² = mi² × 2.58998811

Because both units measure area, the conversion is a single multiplication by a fixed factor. That factor never changes, so the result is exact.

Convert the other way

Square kilometers to square miles →

Related area conversions

All area conversions →

Frequently asked questions

How many square kilometers are in a square mile?
There are 2.59 square kilometers in 1 square mile. The formula is km² = mi² × 2.58998811.
How do you convert square miles to square kilometers?
Use the formula km² = mi² × 2.58998811. For example, 10 square miles equals 25.8999 square kilometers.
Is the square miles to square kilometers conversion exact?
Yes. Square miles and square kilometers are both units of area, related by an exact defined factor. Displayed results are rounded for readability.
What is mi² short for?
mi² is the standard symbol for square mile. km² is the symbol for square kilometer.