Square Kilometers to Square Miles Converter
One Square Kilometer equals 0.3861021585 Square Miles (1 km2 = 0.3861021585 mi2). Multiply a Square Kilometer value by 0.3861021585 to get the equivalent in Square Miles. The calculator is above; the formula and worked examples are below.
Formula
mi2 = km2 × 0.3861021585
Multiply the Square Kilometer value by 0.3861021585 to get the equivalent value in Square Miles.
Example Conversions
1 Square Kilometer (km2)
0.3861021585 Square Mile (mi2)
5 Square Kilometer (km2)
1.930510793 Square Mile (mi2)
10 Square Kilometer (km2)
3.861021585 Square Mile (mi2)
25 Square Kilometer (km2)
9.652553964 Square Mile (mi2)
100 Square Kilometer (km2)
38.61021585 Square Mile (mi2)
Conversion Table
| Square Kilometer (km2) | Square Mile (mi2) |
|---|---|
| 0.1 | 0.03861021585 |
| 0.5 | 0.1930510793 |
| 1 | 0.3861021585 |
| 2 | 0.7722043171 |
| 5 | 1.930510793 |
| 10 | 3.861021585 |
| 25 | 9.652553964 |
| 50 | 19.30510793 |
| 100 | 38.61021585 |
| 250 | 96.52553964 |
| 500 | 193.0510793 |
| 1000 | 386.1021585 |
How to Convert Manually
Use these steps to convert Square Kilometer values to Square Mile without the calculator.
- Write down the value in Square Kilometer (km2) that you want to convert.
- Multiply that value by 0.3861021585.
- For example, 10 Square Kilometers × 0.3861021585 = 3.861021585 Square Miles.
- Label the result as Square Mile (mi2).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Square Kilometer and one Square Mile.
About Square Kilometer and Square Mile
The square kilometer is one million square meters. Geography uses it for cities, lakes, parks, and countries, anything too large for hectares. The square mile is 640 acres, about 2.59 square kilometers. US geography uses it for counties, cities, and large land areas. One Square Kilometer equals 0.3861021585 Square Miles (1 km2 = 0.3861021585 mi2). Square Kilometer is used in city and country land areas and in national parks and nature reserves. Square Mile is used in US city and county areas.
Precision and Rounding:Area factors are the squares of exact length factors, so they are exact too (1 ft² = 0.09290304 m² precisely). Whole numbers usually suffice for rooms and land parcels; surveying and legal land descriptions carry four or more decimal places.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15Square Kilometers equals5.791532378Square Miles.
15 km2 × 0.3861021585 = 5.791532378 mi2
FAQ
How do I convert Square Kilometer to Square Mile?
Multiply the Square Kilometer value by 0.3861021585 to get the equivalent value in Square Miles.
What is the formula for Square Kilometer to Square Mile?
The formula is mi2 = km2 × 0.3861021585.
How many Square Miles are in 1 Square Kilometer?
1 Square Kilometer equals 0.3861021585 Square Miles.
Can I convert Square Mile back to Square Kilometer?
Yes. 1 Square Mile equals 2.58998811 Square Kilometers, and the related converter can reverse the calculation.
What are common names for Square Kilometer and Square Mile?
Square Kilometer is shown as km2 and may also be searched as square kilometers, sq km, km². Square Mile is shown as mi2 and may also be searched as square miles, sq mi, mi².
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