Convert Acre to Square US Survey Foot
Convert acres to square us survey feet instantly. 1 acre = 43559.8257617097 square us survey foot — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square US Survey Foot to Acre converter for the reverse conversion.
Units explained
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 Foot
A square US survey foot is a unit of area equal to approximately 0.0929034116 m². It is slightly larger than the square international foot due to historical surveying definitions.
Derived by squaring the US survey foot, which was defined as exactly 1200/3937 meter from 1893 to 2023. This produced a value about 2 parts per million larger than the international foot.
Square US survey feet appear in legacy US public land records and state plane coordinate systems established before 2023. The US officially retired the survey foot effective January 1, 2023.
Defined in 1893; officially retired January 2023, but legacy records remain.
Acre to Square US Survey Foot conversion formula
The relationship between acres and square us survey feet:
To convert acres to square us survey feet, multiply the value in acres by 43559.8257617097. To reverse, multiply square us survey feet by 2.295693e-5.
How to use this converter
Type a value into the calculator. The result in square us survey feet updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Square US Survey Foot to Acre converter for the reverse direction.
Step-by-step: convert acres to square us survey feet
- Write down the value in acres (ac).
- Multiply that value by the factor 43559.8257617097.
- The product is the equivalent value in square us survey feet (sft²).
- To reverse, multiply the square us survey foot value by 2.295693e-5.
Worked examples
Example 1 — Convert 1 ac to sft²:
1 × 43559.8257617097 = 43559.8257617097 sft²
Example 2 — Convert 100 ac to sft²:
100 × 43559.8257617097 = 4355982.5761709725 sft²
Real-world example — Geographic to architectural scale
One acre equals 100,000 square us survey feet. Map scales use this when an architectural site plan (in the smaller unit) must be related to road-network plans (in the larger unit) on the same drawing.
1 ac × 43559.8257617097 = 43559.8257617097 sft²
Real-world example — Geographic to architectural conversion
One acre equals 100,000 square us survey feet. The conversion bridges geographic-scale survey work and architectural-scale building plans on the same drawing.
1 ac × 43559.8257617097 = 43559.8257617097 sft²
Acre to Square US Survey Foot conversion table
Standard reference values for converting acres to square us survey feet:
| Acre [ac] | Square US Survey Foot [sft²] |
|---|---|
| 0.01 | 435.5982576171 |
| 0.1 | 4355.982576171 |
| 1 | 43559.8257617097 |
| 2 | 87119.6515234195 |
| 3 | 130679.4772851292 |
| 4 | 174239.3030468389 |
| 5 | 217799.1288085486 |
| 10 | 435598.2576170972 |
| 20 | 871196.5152341945 |
| 30 | 1306794.7728512918 |
| 40 | 1742393.0304683889 |
| 50 | 2177991.2880854863 |
| 100 | 4355982.5761709725 |
| 500 | 2.177991e+7 |
| 1000 | 4.355983e+7 |
Frequently asked questions
How many square us survey feet is 1 acre?
How do I convert acres to square us survey feet?
How do I convert square us survey feet back to acres?
How many square us survey feet is 100 acres?
Popular area unit conversions
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Metric / SI (16 units)
Imperial / US Customary (14 units)
US Survey (5 units)
Indian Subcontinent (16 units)
Other Regional (10 units)
Scientific / Physics (5 units)
Historical / Pre-metric European (6 units)
Sources & references
Conversion factor (1 ac = 43559.8257617097 sft²) 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.