How to convert square kilometres to square miles
One square kilometre equals 0.386102 square miles, so multiply the number of square kilometres by 0.386102:
mi² = km² × 0.386102
km² = mi² ÷ 0.386102 (1 mi² = 2.59 km²)
Example: 2.59 km² → 2.59 × 0.386102 = 1 mi².
Going the other way, divide by 0.386102, or multiply by 2.59; the square miles to square kilometres converter does it for you.
Everyday values
| Square kilometres | Square miles | For example |
|---|---|---|
| 1 km² | 0.386102 mi² | one square kilometre |
| 2.59 km² | 1 mi² | one square mile |
| 100 km² | 38.6102 mi² | a mid-sized city's area, roughly |
| 1,000 km² | 386.102 mi² | 1,000 km² |
When you need this conversion
One square kilometre is 0.386 square miles. City, park and country areas are given in km² almost everywhere except the US and UK.
Square kilometre to square mile conversion table
| km² | mi² | km² | mi² |
|---|---|---|---|
| 1 km² | 0.386102 mi² | 13 km² | 5.0193 mi² |
| 2 km² | 0.772204 mi² | 14 km² | 5.4054 mi² |
| 3 km² | 1.1583 mi² | 15 km² | 5.7915 mi² |
| 4 km² | 1.5444 mi² | 16 km² | 6.1776 mi² |
| 5 km² | 1.9305 mi² | 17 km² | 6.5637 mi² |
| 6 km² | 2.3166 mi² | 18 km² | 6.9498 mi² |
| 7 km² | 2.7027 mi² | 19 km² | 7.3359 mi² |
| 8 km² | 3.0888 mi² | 20 km² | 7.722 mi² |
| 9 km² | 3.4749 mi² | 21 km² | 8.1082 mi² |
| 10 km² | 3.861 mi² | 22 km² | 8.4943 mi² |
| 11 km² | 4.2471 mi² | 23 km² | 8.8804 mi² |
| 12 km² | 4.6332 mi² | 24 km² | 9.2665 mi² |
About the units
- Square kilometre (km²): 1,000,000 m², or 100 hectares.
- Square mile (mi²): 640 acres, about 2.59 km².
Both are units of area. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many square miles are in one square kilometre?
One square kilometre is 0.386102 square miles. One square mile is 2.59 square kilometres.
How do I convert square kilometres to square miles?
Multiply the value in square kilometres by 0.386102. To go back, divide by 0.386102.
What is 2.59 km² in square miles?
2.59 km² = 1 mi².
What is 100 km² in square miles?
100 km² = 38.6102 mi².
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.