About the Square Mile Converter
Convert square miles (mi²) to square kilometers (km²) instantly. Includes the exact conversion factor, formula and a quick reference table.
Also known as: mi² to km², Square miles to Square kilometers, convert Square miles to Square kilometers, mi2 to km2, sq mi to sq km, square miles to km2.
How to use this calculator
- Enter value in square miles.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Open “Step-by-step” to see how the answer was worked out.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
km² = mi² × 2.5899881103
Worked example
Using the values pre-filled in the calculator above:
- Value in square miles = 1 mi²
the calculator returns:
- Square kilometers: 2.589988 km²
- Square millimeters: 2,589,988,110,336 mm²
- Square centimeters: 25,899,881,103.36 cm²
- Square meters: 2,589,988.11 m²
Working
1 mi² × 2.5899881103 = 2.58998811 km²