Square kilometers to Square miles Converter
Convert square kilometers to square miles instantly. Exact factor: 1 km² = 0.3861 mi².
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Convert square kilometers to square miles
The exact conversion factor is 1 km² = 0.3861 mi². Type any value and the result updates instantly; the math is shown beneath the board.
Worked by hand
Multiply the square kilometers value by 2.59 (that is, 1 ÷ 0.3861) to get square miles.
Worked example
- Take 1 km²
- multiply by 2.59
- the result is 0.3861 mi²
How to use it
- Enter your square kilometers
- Read the square miles result
- Check the factor line to verify by hand
Frequently asked questions
How many square miles are in one square kilometers?
Exactly 0.3861 mi², by the SI/NIST definition.
How do I convert square miles back to square kilometers?
Divide by 0.3861 — or use the full converter where both directions are one click.
Is this rounding or exact?
The factor is exact; only the displayed decimals are rounded.