Convert Chain to Mile
Convert chains to miles instantly. 1 chain = 0.0125 mile — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Mile to Chain converter for the reverse conversion.
Units explained
Chain
A chain is an Imperial unit of length equal to 66 feet (20.1168 m), or exactly 4 rods or 100 links. It is the central unit in the Gunter chain-based land-survey system.
Defined by Edmund Gunter in 1620 specifically to make land-area arithmetic easy: 10 square chains = 1 acre exactly. The 66-foot length and 100-link subdivision were chosen so chain measurements could be added decimally.
Chains are the fundamental unit of legacy US public land surveys (the entire US township-and-range system uses chains). Modern survey work generally uses meters or feet, but legacy deeds remain in chains.
Invented by Edmund Gunter in 1620; standardised throughout English and American land survey; became exact via the 1959 International Yard and Pound Agreement.
Mile
A mile (statute mile) is an Imperial and US customary unit of length equal to 5,280 feet or exactly 1,609.344 meters. It is the standard unit for road distances in the United States and the United Kingdom.
The mile derives from the Roman mille passus ("thousand paces" — about 1,480 meters). The English statute mile was fixed at 5,280 feet by the Weights and Measures Act of 1593, and exactly defined as 1,609.344 m by the 1959 International Yard and Pound Agreement.
Miles are used in the US and UK for road signs, speed limits (mph), athletic events (one-mile run), and geographic distances. Aviation also uses statute miles for some visibility measurements.
Roman origin (mille passus); English statute mile fixed at 5,280 feet in 1593; standardized to 1,609.344 m exactly by the 1959 International Yard and Pound Agreement.
Chain to Mile conversion formula
The relationship between chains and miles:
To convert chains to miles, multiply the value in chains by 0.0125. To reverse, multiply miles by 80.
How to use this converter
Type a value into the calculator. The result in miles updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Mile to Chain converter for the reverse direction.
Step-by-step: convert chains to miles
- Write down the value in chains (ch).
- Multiply that value by the factor 0.0125.
- The product is the equivalent value in miles (mi).
- To reverse, multiply the mile value by 80.
Worked examples
Example 1 — Convert 1 ch to mi:
1 × 0.0125 = 0.0125 mi
Example 2 — Convert 100 ch to mi:
100 × 0.0125 = 1.25 mi
Chain to Mile conversion table
Standard reference values for converting chains to miles:
| Chain [ch] | Mile [mi] |
|---|---|
| 0.01 | 0.000125 |
| 0.1 | 0.00125 |
| 1 | 0.0125 |
| 2 | 0.025 |
| 3 | 0.0375 |
| 4 | 0.05 |
| 5 | 0.0625 |
| 10 | 0.125 |
| 20 | 0.25 |
| 30 | 0.375 |
| 40 | 0.5 |
| 50 | 0.625 |
| 100 | 1.25 |
| 500 | 6.25 |
| 1000 | 12.5 |
Frequently asked questions
How many miles is 1 chain?
How do I convert chains to miles?
How do I convert miles back to chains?
How many miles is 100 chains?
Popular length unit conversions
Convert Chain to other length units
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 ch = 0.0125 mi) 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.