Convert Section to Acre
Convert sections to acres instantly. 1 section = 640 acre — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Acre to Section converter for the reverse conversion.
Units explained
Section
A section is a unit of area used in the US Public Land Survey System, equal to 1 square mile (640 acres or approximately 2.59 km²).
Defined by the Land Ordinance of 1785 as 1/36 of a township. Sections are numbered 1-36 within each township.
Sections are the fundamental unit of US public land records in PLSS states (essentially the central and western US). Property descriptions like 'NE quarter of section 14, township 3 north, range 2 east' use this system.
Defined by the US Land Ordinance of 1785.
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.
Section to Acre conversion formula
The relationship between sections and acres:
To convert sections to acres, multiply the value in sections by 640. To reverse, multiply acres by 0.0015625.
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 Section converter for the reverse direction.
Step-by-step: convert sections to acres
- Write down the value in sections (sec).
- Multiply that value by the factor 640.
- The product is the equivalent value in acres (ac).
- To reverse, multiply the acre value by 0.0015625.
Worked examples
Example 1 — Convert 1 sec to ac:
1 × 640 = 640 ac
Example 2 — Convert 100 sec to ac:
100 × 640 = 64000 ac
Section to Acre conversion table
Standard reference values for converting sections to acres:
| Section [sec] | Acre [ac] |
|---|---|
| 0.01 | 6.4 |
| 0.1 | 64 |
| 1 | 640 |
| 2 | 1280 |
| 3 | 1920 |
| 4 | 2560 |
| 5 | 3200 |
| 10 | 6400 |
| 20 | 12800 |
| 30 | 19200 |
| 40 | 25600 |
| 50 | 32000 |
| 100 | 64000 |
| 500 | 320000 |
| 1000 | 640000 |
Frequently asked questions
How many acres is 1 section?
How do I convert sections to acres?
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How many acres is 100 sections?
Popular area unit conversions
Convert Section to other area units
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Metric / SI (5 units)
Imperial / US Customary (3 units)
Sources & references
Conversion factor (1 sec = 640 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 Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.