Acre to Square Mile (US Survey) Converter
Unit Converter
Instant · Precise · Universal
23 units available
6 categories total
How to Convert Acre to Square Mile (US Survey)
To convert acres to hectares: multiply by 0.4047. To m²: multiply by 4,046.86. To ft²: multiply by 43,560.
1 acre = 43,560 ft² = 4,840 yd² = 4,046.86 m² ≈ 0.4047 ha. 640 acres = 1 mi².
For example, 1 Acre (ac) = 0.00156249375 Square Mile (US Survey) (mi² (US)).
Acre to Square Mile (US Survey) — Common Values
| Acre (ac) | Square Mile (US Survey) (mi² (US)) |
|---|---|
| 0.1 | 0.000156249375 |
| 0.5 | 0.000781246875 |
| 1 | 0.00156249375 |
| 2 | 0.0031249875 |
| 5 | 0.00781246875 |
| 10 | 0.0156249375 |
| 25 | 0.03906234375 |
| 50 | 0.0781246875 |
| 100 | 0.156249375 |
| 500 | 0.781246875 |
| 1000 | 1.56249375 |
About Acre (ac)
Definition
The acre is a unit of area equal to 43,560 square feet (4,046.86 m²), historically the area a team of oxen could plow in one day.
Mathematical Relationship
1 acre = 43,560 ft² = 4,840 yd² = 4,046.86 m² ≈ 0.4047 ha. 640 acres = 1 mi².
Conversion Formula
To convert acres to hectares: multiply by 0.4047. To m²: multiply by 4,046.86. To ft²: multiply by 43,560.
Practical Applications
Real estate listings, farmland area, lot sizes, park acreages, and zoning regulations.
Interesting Facts
A US football field (including end zones) is about 1.32 acres. Central Park in NYC is 843 acres. An acre is about 75% of a football field.
Common Mistakes
Thinking an acre is a square shape — it can be any shape with the right total area. Also, confusing acre with hectare (1 acre ≈ 0.4 ha).
Educational Tips
Imagine a football field without the end zones — that's roughly 1 acre. Or 16 tennis courts side by side.
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.