Square Mile (US Survey) to Acre (US Survey) Converter
Unit Converter
Instant · Precise · Universal
23 units available
6 categories total
How to Convert Square Mile (US Survey) to Acre (US Survey)
To convert US survey mi² to km²: multiply by 2.590. To international mi²: multiply by ~1.000004.
1 mi² (US) ≈ 2,589,998.47 m². Differs from international mi² (2,589,988.11 m²) by about 10.36 m².
For example, 1 Square Mile (US Survey) (mi² (US)) = 640 Acre (US Survey) (ac (US)).
Square Mile (US Survey) to Acre (US Survey) — Common Values
| Square Mile (US Survey) (mi² (US)) | Acre (US Survey) (ac (US)) |
|---|---|
| 0.1 | 64 |
| 0.5 | 320 |
| 1 | 640 |
| 2 | 1280 |
| 5 | 3200 |
| 10 | 6400 |
| 25 | 16000 |
| 50 | 32000 |
| 100 | 64000 |
| 500 | 320000 |
| 1000 | 640000 |
About Square Mile (US Survey) (mi² (US))
Definition
The US survey square mile is a historical area unit based on the US survey foot, equal to approximately 2,589,998.47 m².
Mathematical Relationship
1 mi² (US) ≈ 2,589,998.47 m². Differs from international mi² (2,589,988.11 m²) by about 10.36 m².
Conversion Formula
To convert US survey mi² to km²: multiply by 2.590. To international mi²: multiply by ~1.000004.
Practical Applications
Historical US Public Land Survey System sections (each nominally 1 mi² US survey).
Interesting Facts
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.
Common Mistakes
Using the US survey mile for new calculations. Deprecated since 2023 — use the international definitions.
Educational Tips
The US Survey system was a legacy from 1893. Its 2023 retirement unified US measurements with the international standard.
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.