Acre (US Survey) to Square Kilometer Converter
Unit Converter
Instant · Precise · Universal
23 units available
6 categories total
How to Convert Acre (US Survey) to Square Kilometer
To convert US survey acres to m²: multiply by 4,046.873. To international acres: multiply by ~1.000004.
1 US survey acre ≈ 4,046.873 m². Differs from international acre (4,046.856 m²) by about 0.016 m².
For example, 1 Acre (US Survey) (ac (US)) = 0.00404687261 Square Kilometer (km²).
Acre (US Survey) to Square Kilometer — Common Values
| Acre (US Survey) (ac (US)) | Square Kilometer (km²) |
|---|---|
| 0.1 | 0.000404687261 |
| 0.5 | 0.002023436305 |
| 1 | 0.00404687261 |
| 2 | 0.00809374522 |
| 5 | 0.02023436305 |
| 10 | 0.0404687261 |
| 25 | 0.1011718152 |
| 50 | 0.2023436305 |
| 100 | 0.404687261 |
| 500 | 2.023436305 |
| 1000 | 4.04687261 |
About Acre (US Survey) (ac (US))
Definition
The US survey acre is a historical unit of area based on the US survey foot, equal to approximately 4,046.873 m².
Mathematical Relationship
1 US survey acre ≈ 4,046.873 m². Differs from international acre (4,046.856 m²) by about 0.016 m².
Conversion Formula
To convert US survey acres to m²: multiply by 4,046.873. To international acres: multiply by ~1.000004.
Practical Applications
Historical US land surveys, old property deeds, and State Plane Coordinate System calculations.
Interesting Facts
The difference between US survey and international acre is about 0.016 m² — roughly the area of a sheet of paper. Over large areas, it adds up.
Common Mistakes
Using US survey acre in new calculations — it's been deprecated since 2023. Use the international acre instead.
Educational Tips
As of 2023, the US survey foot and acre are retired. All US measurements now use the international definitions.
About Square Kilometer (km²)
Definition
The square kilometer is a metric unit of area equal to 1,000,000 square meters, or a square with sides of 1 kilometer.
Mathematical Relationship
1 km² = 1,000,000 m² = 100 ha = 247.105 acres ≈ 0.3861 mi².
Conversion Formula
To convert km² to mi²: multiply by 0.3861. To hectares: multiply by 100. To acres: multiply by 247.105.
Practical Applications
Country areas, national park sizes, city footprints, forest coverage, and watershed boundaries.
Interesting Facts
Vatican City = 0.44 km². Manhattan = 59.1 km². Russia = 17,098,242 km² (largest country). Earth's surface = 510,072,000 km².
Common Mistakes
Thinking 1 km² = 1,000 m² (it's actually 1,000,000 m²). Area scales as the square of the linear dimension.
Educational Tips
1 km = 1,000 m, but 1 km² = 1,000² m² = 1,000,000 m². Always square the conversion factor for area.