---
title: "Square kilometers to Square miles — km² to mi² converter"
description: "1 square kilometer = 0.3861 square miles. Convert square kilometers to square miles with a full conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/square-km-to-square-miles/
site: "At One Place"
---

# Square kilometers to square miles

**1 square kilometer in square miles: 1 km² = 0.3861 mi²**

mi² = km² × 0.3861021585

To convert square kilometers to square miles, multiply by 0.3861021585. The table below gives the values people look up most often, and the converter works for any number.

## Square kilometers to square miles table

*Common square kilometer values converted to square miles.*

| Square kilometers | Square miles |
| --- | --- |
| 1 km² | 0.3861 |
| 2 km² | 0.7722 |
| 3 km² | 1.158306 |
| 4 km² | 1.544409 |
| 5 km² | 1.930511 |
| 10 km² | 3.861022 |
| 15 km² | 5.791532 |
| 20 km² | 7.722043 |
| 25 km² | 9.652554 |
| 30 km² | 11.58306 |
| 40 km² | 15.44409 |
| 50 km² | 19.30511 |
| 75 km² | 28.95766 |
| 100 km² | 38.61022 |
| 250 km² | 96.52554 |
| 500 km² | 193.0511 |
| 1,000 km² | 386.1022 |

## How the conversion works

The relationship is mi² = km² × 0.3861021585. Both units measure area, so the conversion is a fixed factor that never changes.

## Common questions

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

One square kilometer equals 0.3861 square miles. mi² = km² × 0.3861021585.

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

Use mi² = km² × 0.3861021585. So 10 km² is 3.861022 mi².

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

One square mile equals 2.589988 square kilometers, which is the reverse of the conversion above.

## Related pages

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