Convert Square Mile to Square Chain
Convert square miles to square chains instantly. 1 square mile = 6400.0000006326 square chain — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Chain to Square Mile converter for the reverse conversion.
Units explained
Square Mile
A square mile is an imperial unit of area equal to exactly 2,589,988.110336 m². It is used for measuring large land areas in the United States and the United Kingdom.
Derived by squaring the statute mile (5,280 feet). The mile was standardized via the 1959 International Yard and Pound Agreement.
Square miles are used for US and UK regional geography (county areas, lake sizes, large parks), national statistics, and military range descriptions. 1 mi² = 640 acres = 2.589988 km².
Mile dates to Roman antiquity; 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.
Square Mile to Square Chain conversion formula
The relationship between square miles and square chains:
To convert square miles to square chains, multiply the value in square miles by 6400.0000006326. To reverse, multiply square chains by 0.00015625.
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 Square Mile converter for the reverse direction.
Step-by-step: convert square miles to square chains
- Write down the value in square miles (mi²).
- Multiply that value by the factor 6400.0000006326.
- The product is the equivalent value in square chains (ch²).
- To reverse, multiply the square chain value by 0.00015625.
Worked examples
Example 1 — Convert 1 mi² to ch²:
1 × 6400.0000006326 = 6400.0000006326 ch²
Example 2 — Convert 100 mi² to ch²:
100 × 6400.0000006326 = 640000.000063259 ch²
Square Mile to Square Chain conversion table
Standard reference values for converting square miles to square chains:
| Square Mile [mi²] | Square Chain [ch²] |
|---|---|
| 0.01 | 64.0000000063 |
| 0.1 | 640.0000000633 |
| 1 | 6400.0000006326 |
| 2 | 12800.0000012652 |
| 3 | 19200.0000018978 |
| 4 | 25600.0000025304 |
| 5 | 32000.0000031629 |
| 10 | 64000.0000063259 |
| 20 | 128000.0000126518 |
| 30 | 192000.0000189777 |
| 40 | 256000.0000253036 |
| 50 | 320000.0000316295 |
| 100 | 640000.000063259 |
| 500 | 3200000.0003162948 |
| 1000 | 6400000.0006325897 |
Frequently asked questions
How many square chains is 1 square mile?
How do I convert square miles to square chains?
How do I convert square chains back to square miles?
How many square chains is 100 square miles?
Popular area unit conversions
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Metric / SI (5 units)
Imperial / US Customary (14 units)
Sources & references
Conversion factor (1 mi² = 6400.0000006326 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 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.