Instant · Precise · Universal
23 units available
6 categories total
To convert km² to mi²: multiply by 0.3861. To hectares: multiply by 100. To acres: multiply by 247.105.
1 km² = 1,000,000 m² = 100 ha = 247.105 acres ≈ 0.3861 mi².
For example, 1 Square Kilometer (km²) = 0.3861006141 Square Mile (US Survey) (mi² (US)).
| Square Kilometer (km²) | Square Mile (US Survey) (mi² (US)) |
|---|---|
| 0.1 | 0.03861006141 |
| 0.5 | 0.1930503071 |
| 1 | 0.3861006141 |
| 2 | 0.7722012283 |
| 5 | 1.930503071 |
| 10 | 3.861006141 |
| 25 | 9.652515353 |
| 50 | 19.30503071 |
| 100 | 38.61006141 |
| 500 | 193.0503071 |
| 1000 | 386.1006141 |
The square kilometer is a metric unit of area equal to 1,000,000 square meters, or a square with sides of 1 kilometer.
1 km² = 1,000,000 m² = 100 ha = 247.105 acres ≈ 0.3861 mi².
To convert km² to mi²: multiply by 0.3861. To hectares: multiply by 100. To acres: multiply by 247.105.
Country areas, national park sizes, city footprints, forest coverage, and watershed boundaries.
Vatican City = 0.44 km². Manhattan = 59.1 km². Russia = 17,098,242 km² (largest country). Earth's surface = 510,072,000 km².
Thinking 1 km² = 1,000 m² (it's actually 1,000,000 m²). Area scales as the square of the linear dimension.
1 km = 1,000 m, but 1 km² = 1,000² m² = 1,000,000 m². Always square the conversion factor for area.
The US survey square mile is a historical area unit based on the US survey foot, equal to approximately 2,589,998.47 m².
1 mi² (US) ≈ 2,589,998.47 m². Differs from international mi² (2,589,988.11 m²) by about 10.36 m².
To convert US survey mi² to km²: multiply by 2.590. To international mi²: multiply by ~1.000004.
Historical US Public Land Survey System sections (each nominally 1 mi² US survey).
Over one square mile, the US survey definition differs from the international definition by about 10.4 m² — roughly a 3 m × 3.5 m room.
Using the US survey mile for new calculations. Deprecated since 2023 — use the international definitions.
The US Survey system was a legacy from 1893. Its 2023 retirement unified US measurements with the international standard.



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