---
title: "Square miles to Square kilometers — mi² to km² converter"
description: "1 square mile = 2.589988 square kilometers. Conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/square-miles-to-square-km/
site: "At One Place"
---

# Square miles to square kilometers

**1 square mile in square kilometers: 1 mi² = 2.589988 km²**

km² = mi² × 2.58998811

To convert square miles to square kilometers, multiply by 2.58998811. The table below gives the values people look up most often, and the converter works for any number.

## Square miles to square kilometers table

*Common square mile values converted to square kilometers.*

| Square miles | Square kilometers |
| --- | --- |
| 1 mi² | 2.589988 |
| 2 mi² | 5.179976 |
| 3 mi² | 7.769964 |
| 4 mi² | 10.35995 |
| 5 mi² | 12.94994 |
| 10 mi² | 25.89988 |
| 15 mi² | 38.84982 |
| 20 mi² | 51.79976 |
| 25 mi² | 64.7497 |
| 30 mi² | 77.69964 |
| 40 mi² | 103.5995 |
| 50 mi² | 129.4994 |
| 75 mi² | 194.2491 |
| 100 mi² | 258.9988 |
| 250 mi² | 647.497 |
| 500 mi² | 1,294.9941 |
| 1,000 mi² | 2,589.9881 |

## How the conversion works

The relationship is km² = mi² × 2.58998811. Both units measure area, so the conversion is a fixed factor that never changes.

## Common questions

### How many square kilometers are in one square mile?

One square mile equals 2.589988 square kilometers. km² = mi² × 2.58998811.

### How do you convert square miles to square kilometers?

Use km² = mi² × 2.58998811. So 10 mi² is 25.89988 km².

### How many square miles are in one square kilometer?

One square kilometer equals 0.3861 square miles, which is the reverse of the conversion above.

## Related pages

- [Square kilometers to Square miles](https://atoneplace.net/convert/square-km-to-square-miles/)
- [Square miles to Square meters](https://atoneplace.net/convert/square-miles-to-square-meters/)
- [Square miles to Hectares](https://atoneplace.net/convert/square-miles-to-hectares/)
- [Square miles to Acres](https://atoneplace.net/convert/square-miles-to-acres/)
- [Square miles to Square feet](https://atoneplace.net/convert/square-miles-to-square-feet/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)