Square miles to square kilometers
1 square mile = 2.58999 square kilometers
Type a value in square miles (sq mi) to get square kilometers (km²) straight away. A square mile is larger than a square kilometer, so the number goes up. Both units belong to area, measured here against the square meter.
1 sq mi = 2.5899881 km²
Formula
km² = sq mi × 2.5899881
One square mile is 2.5899881 square kilometers, so multiply the square mile value by that factor. Here sq mi is the value in square miles and km² is the result in square kilometers.
Worked example: 2 square miles × 2.5899881 = 5.17998 square kilometers.
Square miles to square kilometers table
| square miles (sq mi) | square kilometers (km²) |
|---|---|
| 1 sq mi | 2.58999 km² |
| 2 sq mi | 5.17998 km² |
| 3 sq mi | 7.76996 km² |
| 4 sq mi | 10.36 km² |
| 5 sq mi | 12.9499 km² |
| 6 sq mi | 15.5399 km² |
| 7 sq mi | 18.1299 km² |
| 8 sq mi | 20.7199 km² |
| 9 sq mi | 23.3099 km² |
| 10 sq mi | 25.8999 km² |
| 15 sq mi | 38.8498 km² |
| 20 sq mi | 51.7998 km² |
| 25 sq mi | 64.7497 km² |
| 30 sq mi | 77.6996 km² |
| 40 sq mi | 103.6 km² |
| 50 sq mi | 129.499 km² |
| 60 sq mi | 155.399 km² |
| 75 sq mi | 194.249 km² |
| 100 sq mi | 258.999 km² |
Everyday square miles in square kilometers
| What it is | sq mi | km² |
|---|---|---|
| 640 acres | 1 sq mi | 2.58999 km² |
| a small town | 5 sq mi | 12.9499 km² |
| Manhattan (about) | 22.8 sq mi | 59.0517 km² |
| a large town | 100 sq mi | 258.999 km² |
| Delhi (NCT, about) | 573 sq mi | 1,484.06 km² |
Quick estimate in your head
Multiply by about 2.6. For 2 sq mi that gives 5.2 km² against an exact 5.17998 km², an error of 0.4%.
About the units
Square mile (sq mi). 640 acres, about 2.59 km². Used for land area in the US.
Square kilometer (km²). 1,000,000 m² or 100 hectares. Used for city and country areas.
Going the other way, 1 square kilometer is 0.386102 square miles.
Questions
How many square kilometers are in 1 square mile?
1 square mile is 2.58999 square kilometers, and 1 square kilometer is 0.386102 square miles.
How do I convert square miles to square kilometers?
Use km² = sq mi × 2.5899881. For example, 2 square miles × 2.5899881 = 5.17998 square kilometers.
Is the square mile to square kilometer factor exact?
The factor comes from the unit definitions. Results here are rounded to 6 significant digits for display.
How much is Delhi (NCT, about) in square kilometers?
573 sq mi is 1,484.06 km².
Source for the conversion factor: NIST Handbook 44, Appendix C (units of area).
Related conversions
- square kilometers to square miles
- hectares to square kilometers
- square kilometers to hectares
- square meters to square feet
- square feet to square meters
- square yards to square feet