Square Kilometer to Square Mile Converter
Convert square kilometers to square miles (km² to mi²) instantly with this free online area converter. Enter any value in the Square Kilometer field and get the equivalent in Square Mile immediately. This converter handles any quantity — from tiny fractions to large numbers — with full precision. No signup, no ads in the widget, and the conversion runs entirely in your browser for instant results.
The conversion factor is exact: 1 km² = 0.3861021586 mi². To convert square kilometers to square miles, multiply your Square Kilometer value by 0.3861021586. For example, 10 km² = 3.861021586 mi². You can also reverse the calculation: 1 mi² = 2.58998811 km².
Quick conversion table
| Square Kilometer (km²) | Square Mile (mi²) |
|---|---|
| 1 km² | 0.3861021586 mi² |
| 5 km² | 1.930510793 mi² |
| 10 km² | 3.861021586 mi² |
| 25 km² | 9.652553965 mi² |
| 50 km² | 19.30510793 mi² |
| 100 km² | 38.61021586 mi² |
Use the swap button to reverse the direction, or choose a different unit from the dropdown menus to convert within the area category.
Formula
Square Kilometer to Square Mile conversion: 1 km² = 0.3861021586 mi² square miles = square kilometers × 0.3861021586 1 mi² = 2.58998811 km² square kilometers = square miles × 2.58998811
Example
Example: Convert 10 km² to mi²: 10 km² × 0.3861021586 = 3.861021586 mi² So, 10 km² is about 3.861021586 mi². To convert back, multiply by 2.58998811: 3.861021586 mi² × 2.58998811 = 10 km².
How to Use
- Enter the value you want to convert in the Square Kilometer field
- The result in Square Mile appears instantly below
- Use the dropdown menus to change units if needed
- Click 'Swap Units' to reverse the conversion direction
- Copy the result or adjust the input for a new conversion
Frequently Asked Questions
How do I convert square kilometers to square miles?
Enter the value in Square Kilometer (km²) in the 'From' field. The equivalent in Square Mile (mi²) appears instantly in the 'To' field. The converter uses precise conversion factors and updates in real time as you type.
What is the formula to convert km² to mi²?
1 km² = 0.3861021586 mi², so square miles = square kilometers × 0.3861021586. To convert back, 1 mi² = 2.58998811 km². The full formula and a worked example are shown on this page.
How many square miles are in one Square Kilometer?
1 km² = 0.3861021586 mi².
Is this Square Kilometer to Square Mile converter free?
Yes, completely free with no signup, no limits, and no ads in the converter widget. You can convert as many values as you need. The tool runs entirely in your browser, so your data never leaves your device.
Can I convert square miles back to square kilometers?
Yes. Click the 'Swap Units' button to reverse the direction. You can also use the dropdown menus to select any other area unit for either field.
How accurate is the km² to mi² conversion?
The converter uses high-precision conversion factors (up to 8 decimal places). Results are displayed with up to 6 decimal places, with trailing zeros removed for readability. For scientific or engineering work, always verify with official standards.