In 1 square miles there are 2.589988 square kilometer. Meanwhile in 1 square kilometer there are 0.386102 square miles. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Square kilometer to Square miles calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert square miles (mi²) to square kilometers (km²), use the area conversion factor, not the distance factor.
Formula:
Example:
To convert square miles (sq mi) to square kilometers (km²), multiply by 2.58999.
Formula: km² = sq mi × 2.58999
1 square mile = 2.58999 square kilometers.
This value comes from the mile to kilometer length conversion, squared for area.
The standard conversion factor is:
1 sq mi = 2.58999 km²
For quick math, many people round it to 2.59 km².
To convert square kilometers to square miles, divide by 2.58999.
Formula: sq mi = km² ÷ 2.58999
Area units scale by squaring the length conversion.
Since 1 mile = 1.60934 kilometers, the area conversion is 1.60934² = 2.58999.
Yes. km² is the symbol for square kilometer.
Both mean the same area unit.
Yes. sq mi is a common abbreviation for square mile.
You may also see mi², which means the same thing.
Multiply by 2.58999:
5 sq mi = 5 × 2.58999 = 12.94995 km²
Rounded: 12.95 km².
Multiply by 2.58999:
10 sq mi = 25.8999 km²
Rounded: 25.9 km².
Use the same area formula for any surface area, including land:
km² = sq mi × 2.58999
This works for maps, property totals, and region size.
Use a simple round factor:
1 sq mi ≈ 2.59 km²
For a fast estimate, multiply by 2.6 and adjust slightly down.
Divide by 2.58999:
1,000 km² ÷ 2.58999 = 386.102 sq mi
Rounded: 386.1 sq mi.
2.58999 km² per sq mi is accurate for most uses.
For high-precision work, keep more decimal places: 2.5899881103.
Yes. Square miles and square kilometers measure area the same way.
The surface type does not change the conversion.
A common mistake is using the length factor 1.60934 instead of the area factor 2.58999.
For area, always use the squared conversion.
Yes. Both are area units.
Square miles are used more in the United States, while square kilometers are used in most other countries.
The Calculate Box tool to convert square miles to square kilometer uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a square miles value in the box and have it instantly converted to square kilometer.