Square Miles to Square Kilometres

Convert square miles (mi²) to square kilometres (km²) instantly — with formula and reference table.

mi²
km²

Quick answer: 1 mi² = 2.589988 km². To convert square miles to square kilometres, multiply by mi² × 2.589988.

Converting square miles to square kilometres

This converter changes a value in square miles (mi²) into square kilometres (km²). One square mile equals 2.589988 km². One square mile equals 2.59 square kilometres. The conversion runs entirely in your browser — enter a value and the result updates instantly, in either direction.

Formula

km² = mi² × 2.589988

Example

Convert 10 mi² to km²: 10 × 2.589988 = 25.899881 km².

Square Miles to Square Kilometres conversion table

Square Miles (mi²)Square Kilometres (km²)
1 mi²2.589988 km²
2 mi²5.179976 km²
3 mi²7.769964 km²
5 mi²12.949941 km²
10 mi²25.899881 km²
20 mi²51.799762 km²
25 mi²64.749703 km²
50 mi²129.499406 km²
100 mi²258.998811 km²

How to use this converter

  1. Enter a value in the square miles (mi²) field.
  2. Read the converted value in square kilometres (km²) below.
  3. Type into the km² field instead to convert in reverse, or use the swap button.

Frequently asked questions

How many square kilometres are in a square mile?

1 square mile equals 2.59 square kilometres.

How do I convert 50 sq miles to sq km?

50 times 2.59 = 129.5 square kilometres.

How large is a square mile?

A square mile is 640 acres or about 2.59 square kilometres.

Last updated: 2026-05-27 Free · No signup · Works offline Suggest an improvement