Square mile to Square kilometer Converter
Type a value — the answer appears instantly. 1 mi² = 2.58999 km².
Reviewed by the OmniCalc teamMethod verified 2026-07-01
2.58999 square kilometers
= 2,589,990 m²= 27,878,400 ft²
equals 2.58999 square kilometersFormula: km² = mi² × 2.5899881
Square mile to Square kilometer formula
km² = mi² × 2.5899881
Convert 5 square miles to square kilometers
- Start with 5 square miles.
- Multiply by the conversion factor: 5 × 2.58999 = 12.9499.
- So 5 mi² = 12.9499 km².
Square mile to Square kilometer conversion table
| Square miles (mi²) | Square kilometers (km²) |
|---|---|
| 0.01 mi² | 0.0258999 km² |
| 0.1 mi² | 0.258999 km² |
| 0.25 mi² | 0.647497 km² |
| 0.5 mi² | 1.29499 km² |
| 1 mi² | 2.58999 km² |
| 2 mi² | 5.17998 km² |
| 3 mi² | 7.76996 km² |
| 4 mi² | 10.36 km² |
| 5 mi² | 12.9499 km² |
| 6 mi² | 15.5399 km² |
| 7 mi² | 18.1299 km² |
| 8 mi² | 20.7199 km² |
| 9 mi² | 23.3099 km² |
| 10 mi² | 25.8999 km² |
| 15 mi² | 38.8498 km² |
| 20 mi² | 51.7998 km² |
| 25 mi² | 64.7497 km² |
| 30 mi² | 77.6996 km² |
| 40 mi² | 103.6 km² |
| 50 mi² | 129.499 km² |
| 75 mi² | 194.249 km² |
| 100 mi² | 258.999 km² |
| 250 mi² | 647.497 km² |
| 500 mi² | 1,294.99 km² |
| 1,000 mi² | 2,589.99 km² |
| 5,000 mi² | 12,949.9 km² |
| 10,000 mi² | 25,899.9 km² |
Unit definitions
What is a square mile?
The square mile is the area of a one-mile square, containing 640 acres or about 2.59 square kilometres. It is used for large land areas, counties, and statistical regions in the United States. One square mile is roughly 259 hectares.
What is a square kilometer?
The square kilometre is the area of a one-kilometre square, equal to one million square metres or 100 hectares. It is used for measuring cities, regions, and countries. One square kilometre is about 0.386 square miles.
Frequently asked questions
How many square kilometers are in one square mile?
One square mile equals 2.58999 square kilometers (1 mi² = 2.58999 km²).
How do I convert square miles to square kilometers?
Multiply the value in square miles by 2.58999. For example, 10 mi² × 2.58999 = 25.8999 km².
Which is bigger — a square mile or a square kilometer?
A square mile is bigger: one square mile contains 2.58999 square kilometers.
Is this square mile to square kilometer converter free?
Yes — the converter is free, works offline once loaded, and computes instantly in your browser without sending your numbers to a server.
Conversion factors follow international definitions (SI / NIST). Last verified 2026-07-01.