Square Miles to Square Kilometers Converter
Convert sq mi to km²: multiply by 2.589988. 1 sq mi ≈ 2.59 km². Free tool for geography, land, and map scale.
How to Convert Square mile to Square kilometer
Multiply square miles by 2.58998811.
Conversion Formula:
value * 2.58998811Conversion Examples
Example: 1 sq mi to km²
- 1 × 2.589988 ≈ 2.59 km²
≈ 2.59 km²
Standard conversion.
Example: 5 sq mi to km²
- 5 × 2.589988 ≈ 12.95 km²
≈ 12.95 km²
County-scale.
Conversion Chart
| Square mile | Square kilometer |
|---|---|
| 0.5 | 1.29 |
| 1 | 2.59 |
| 2 | 5.18 |
| 5 | 12.95 |
| 10 | 25.9 |
| 20 | 51.8 |
| 50 | 129.5 |
| 100 | 259 |
| 250 | 647.5 |
| 500 | 1295 |
Conversion Formula
sq mi × 2.58998811 = km²
Quick Conversion Tip
Multiply sq mi by ~2.59 for km².
Unit Definitions
Square Mile (mi²)
A square mile is an imperial unit of area equal to the area of a square with sides measuring one mile. It equals 640 acres and is commonly used for large geographic areas, cities, and counties.
1 square mile = 2.58998811 square kilometers = 640 acres = 27,878,400 square feet = 3,097,600 square yards
Square Kilometer (km²)
A square kilometer is a metric unit of area equal to the area of a square with sides measuring one kilometer. It equals 1,000,000 square meters and is commonly used for large geographic areas, cities, and counties.
1 square kilometer = 0.386102 square miles = 1,000,000 square meters = 100 hectares = 247.105 acres
Common Use Cases
- Geography and atlas comparisons.
- Large land holdings (US → metric).
- GIS layer unit changes.
- News and weather area in km².
Understanding the Conversion
1 sq mi ≈ 2.589988 km². Multiply sq mi by 2.589988.
Examples: 1 sq mi ≈ 2.59 km² · 10 sq mi ≈ 25.9 km² · 0.5 sq mi ≈ 1.295 km².
For US/UK maps in miles vs metric GIS and international reports.
Geography and atlas comparisons. The table and FAQ on this page walk through the factor if you need it.
FAQs
How many km² in a square mile?
One square mile equals 2.58998811 square kilometers (about 2.59 km²).
How do you convert sq mi to km²?
Multiply by 2.58998811. Example: 4 sq mi × 2.59 ≈ 10.36 km².
Sq mi vs acres?
1 sq mi = 640 acres. Use acres for farms; km² for metric regional area.