Square Mile to Square Foot (US Survey) Converter
Unit Converter
Instant · Precise · Universal
23 units available
6 categories total
How to Convert Square Mile to Square Foot (US Survey)
To convert mi² to km²: multiply by 2.59. To acres: multiply by 640. To hectares: multiply by 259.
1 mi² = 640 acres = 27,878,400 ft² = 2.59 km² = 259 ha.
For example, 1 Square Mile (mi²) = 27878288.49 Square Foot (US Survey) (ft² (US)).
Square Mile to Square Foot (US Survey) — Common Values
| Square Mile (mi²) | Square Foot (US Survey) (ft² (US)) |
|---|---|
| 0.1 | 2787828.849 |
| 0.5 | 13939144.24 |
| 1 | 27878288.49 |
| 2 | 55756576.97 |
| 5 | 139391442.4 |
| 10 | 278782884.9 |
| 25 | 696957212.2 |
| 50 | 1393914424 |
| 100 | 2787828849 |
| 500 | 13939144240 |
| 1000 | 27878288490 |
About Square Mile (mi²)
Definition
The square mile is an imperial unit of area equal to the area of a square with sides of one mile (2.59 km²).
Mathematical Relationship
1 mi² = 640 acres = 27,878,400 ft² = 2.59 km² = 259 ha.
Conversion Formula
To convert mi² to km²: multiply by 2.59. To acres: multiply by 640. To hectares: multiply by 259.
Practical Applications
City areas, county sizes, population density, land surveys, and geographic comparisons.
Interesting Facts
Manhattan is about 22.8 mi². The state of Texas is 268,596 mi². Rhode Island (smallest US state) is 1,214 mi².
Common Mistakes
1 mi ≈ 1.609 km, but 1 mi² ≈ 2.59 km² (not 1.609). Area conversion squares the factor.
Educational Tips
1 mi² = 640 acres. This 'section' (640 acres) is the basis of the US Public Land Survey System grid.
About Square Foot (US Survey) (ft² (US))
Definition
The US survey square foot is a historical area unit based on the US survey foot (1200/3937 m), equal to approximately 0.09290341 m².
Mathematical Relationship
1 ft² (US) ≈ 0.09290341 m². Differs from international ft² (0.09290304 m²) by about 4 × 10⁻⁷ m².
Conversion Formula
To convert US survey ft² to m²: multiply by 0.09290341. To international ft²: multiply by ~1.000004.
Practical Applications
Historical property records and government land survey documents.
Interesting Facts
The difference from the international square foot is only about 0.4 mm² — negligible for a single measurement, but significant over millions of square feet.
Common Mistakes
Using the US survey foot in new work. Since 2023, only the international foot is valid in the US.
Educational Tips
The US survey foot existed because of a historical definition difference. It's now retired — use the international foot (exactly 0.3048 m).