Convert Square US Survey Mile to Acre
Convert square us survey miles to acres instantly. 1 square us survey mile = 640.0025599287 acre — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Acre to Square US Survey Mile converter for the reverse conversion.
Units explained
Square US Survey Mile
A square US survey mile is approximately 2,589,998 m², slightly larger than the international square mile.
Derived by squaring the US survey mile (5280 US survey feet).
Square US survey miles appear in older US Public Land Survey System records and state plane coordinate systems pre-dating 2023.
Defined in 1893; retired January 2023.
Acre
An acre is an imperial unit of area equal to exactly 4046.8564224 m². It is the most widely used non-metric unit for land area, particularly in the US, UK, and India.
Originally defined in medieval England as the area one yoke of oxen could plow in a day, approximately 40 perches by 4 perches. Standardized via the 1959 International Yard and Pound Agreement.
Acres are the standard land measurement unit in the US (real estate, agriculture), the UK (rural property), and widely used in India (alongside hectares and traditional regional units). 1 acre = 4840 sq yd = 43,560 sq ft = 0.4047 hectare.
Medieval English farming origin; modern exact value standardized in 1959.
Square US Survey Mile to Acre conversion formula
The relationship between square us survey miles and acres:
To convert square us survey miles to acres, multiply the value in square us survey miles by 640.0025599287. To reverse, multiply acres by 0.0015624938.
How to use this converter
Type a value into the calculator. The result in acres updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Acre to Square US Survey Mile converter for the reverse direction.
Step-by-step: convert square us survey miles to acres
- Write down the value in square us survey miles (smi²).
- Multiply that value by the factor 640.0025599287.
- The product is the equivalent value in acres (ac).
- To reverse, multiply the acre value by 0.0015624938.
Worked examples
Example 1 — Convert 1 smi² to ac:
1 × 640.0025599287 = 640.0025599287 ac
Example 2 — Convert 100 smi² to ac:
100 × 640.0025599287 = 64000.2559928725 ac
Square US Survey Mile to Acre conversion table
Standard reference values for converting square us survey miles to acres:
| Square US Survey Mile [smi²] | Acre [ac] |
|---|---|
| 0.01 | 6.4000255993 |
| 0.1 | 64.0002559929 |
| 1 | 640.0025599287 |
| 2 | 1280.0051198574 |
| 3 | 1920.0076797862 |
| 4 | 2560.0102397149 |
| 5 | 3200.0127996436 |
| 10 | 6400.0255992872 |
| 20 | 12800.0511985745 |
| 30 | 19200.0767978617 |
| 40 | 25600.102397149 |
| 50 | 32000.1279964362 |
| 100 | 64000.2559928725 |
| 500 | 320001.2799643623 |
| 1000 | 640002.5599287247 |
Frequently asked questions
How many acres is 1 square us survey mile?
How do I convert square us survey miles to acres?
How do I convert acres back to square us survey miles?
How many acres is 100 square us survey miles?
Popular area unit conversions
Convert Square US Survey Mile to other area units
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Metric / SI (5 units)
Imperial / US Customary (3 units)
Sources & references
Conversion factor (1 smi² = 640.0025599287 ac) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.