Convert Acre to Square Chain
Convert acres to square chains instantly. 1 acre = 10.000000001 square chain — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Chain 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 Chain
A square chain is an imperial unit of area equal to approximately 404.686 m². It equals 1/10 of an acre.
Derived by squaring the chain (66 feet or 22 yards). The chain was defined by Edmund Gunter in 1620 specifically so that 10 square chains equal exactly one acre.
Square chains appear in US Public Land Survey System (PLSS) records and historical English property documents. The 10-to-1 ratio with acres made early survey arithmetic easier.
Defined by Edmund Gunter in 1620 specifically for surveying convenience.
Acre to Square Chain conversion formula
The relationship between acres and square chains:
To convert acres to square chains, multiply the value in acres by 10.000000001. To reverse, multiply square chains by 0.1.
How to use this converter
Type a value into the calculator. The result in square chains 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 Chain to Acre converter for the reverse direction.
Step-by-step: convert acres to square chains
- Write down the value in acres (ac).
- Multiply that value by the factor 10.000000001.
- The product is the equivalent value in square chains (ch²).
- To reverse, multiply the square chain value by 0.1.
Worked examples
Example 1 — Convert 1 ac to ch²:
1 × 10.000000001 = 10.000000001 ch²
Example 2 — Convert 100 ac to ch²:
100 × 10.000000001 = 1000.0000000988 ch²
Real-world example — Maritime exclusion zone
A 200-acre exclusion zone (a common maritime boundary) converts to a different value in square chains that's useful when describing the same zone in everyday land-distance units.
200 ac × 10.000000001 = 2000.0000001977 ch²
Real-world example — Coastal cruise distances
A 10-acre coastal sailing route converts to a different value in square chains — useful for cruise operators who switch between maritime, aviation, and road-distance units depending on the leg of the trip.
10 ac × 10.000000001 = 100.0000000099 ch²
Real-world example — Road-sign distances across systems
A 100-acre road sign converts cleanly into square chains — exactly the conversion drivers planning trips abroad rely on when reading road signs in a different measurement system.
100 ac × 10.000000001 = 1000.0000000988 ch²
Acre to Square Chain conversion table
Standard reference values for converting acres to square chains:
| Acre [ac] | Square Chain [ch²] |
|---|---|
| 0.01 | 0.1 |
| 0.1 | 1.0000000001 |
| 1 | 10.000000001 |
| 2 | 20.000000002 |
| 3 | 30.000000003 |
| 4 | 40.000000004 |
| 5 | 50.0000000049 |
| 10 | 100.0000000099 |
| 20 | 200.0000000198 |
| 30 | 300.0000000297 |
| 40 | 400.0000000395 |
| 50 | 500.0000000494 |
| 100 | 1000.0000000988 |
| 500 | 5000.0000004942 |
| 1000 | 10000.0000009884 |
Frequently asked questions
How many square chains is 1 acre?
How do I convert acres to square chains?
How do I convert square chains back to acres?
How many square chains is 100 acres?
Popular area unit conversions
Convert Acre to other area units
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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 = 10.000000001 ch²) 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.