A surveyor's chain is 66 feet.
Chains to Nautical miles Converter — ch to nmi
Convert Chain (ch) to Nautical mile (nmi) using the exact conversion factor (1 chain = 0.010862203 nautical mile). See the formula, worked examples, conversion table, history, and common uses.
Chains to Nautical miles converter
Converter
Length Converter
Convert SI, imperial, US customary, astronomical, scientific, and historical length units.
Context values
Some unit families need one extra value for a physically accurate result.
A nautical mile is exactly 1,852 meters.
Result = input x 20.1168 / 1852.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Chains to Nautical miles
Chain and Nautical mile both measure length. Specifically: A surveyor's chain is 66 feet, and a nautical mile is exactly 1,852 meters.
Formula
nautical miles = chains × 0.0108622030238
This factor comes from each unit's defined relationship to the category's base unit: 1 chain equals 20.1168 base units, and 1 nautical mile equals 1852 base units, so dividing one by the other gives the direct chain-to-nautical mile factor of 0.0108622030238.
Simple example
1 ch × 0.01086220302 = 0.010862203 nmi
1 chain = 0.010862203 nautical miles.
Real-world example
10 ch × 0.01086220302 = 0.1086220302 nmi
10 chains = 0.1086220302 nautical miles.
Conversion table
| Chain (ch) | Nautical mile (nmi) |
|---|---|
| 1 ch | 0.010862203 nmi |
| 5 ch | 0.0543110151 nmi |
| 10 ch | 0.1086220302 nmi |
| 21.0975 ch | 0.2291653283 nmi |
| 42.195 ch | 0.4583306566 nmi |
| 100 ch | 1.086220302 nmi |
Reverse conversion: Nautical mile to Chain
0.010862203 nmi × 92.06235584 = 0.9999999978 ch
0.010862203 nautical miles = 0.9999999978 chains.
chains = nautical miles × 92.0623558419
For a page dedicated to this direction, see Nautical mile to Chain.
Understanding the Chain (ch)
A surveyor's chain is 66 feet.
Understanding the Nautical mile
Nautical mile (nmi) measures distance. The international nautical mile is defined as exactly 1,852 meters, standardized in 1929. It is classified as a Non-SI unit accepted for use with SI (maritime/aviation).
Where it's used: Used internationally in maritime navigation and aviation.
Uses of the Nautical mile today
- Marine and aviation distance and navigation
- Basis for the knot (nautical miles per hour)
History of the Nautical mile
The nautical mile was historically defined as one minute of latitude along a meridian, directly tying sea navigation to the Earth's geometry, which made it practical for chart-based navigation using a ship's known latitude. The International Hydrographic Bureau standardized it at exactly 1,852 meters in 1929, a value close to the traditional latitude-based definitions used by different countries.
Historical origin. Nautical mile was not the invention of a single named person; it developed through the process described above.
Nautical mile — sources
- BIPM SI Brochure — Non-SI units accepted for use with SI — Lists the nautical mile among accepted non-SI units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many nautical miles are in 1 chain?
1 chain equals 0.010862203 nautical miles, using the exact defined conversion factor rather than an estimate.
How do I convert chain to nautical mile?
Multiply the chain value by 0.01086220302. The converter above does this instantly to whatever precision you set.
How do I convert nautical mile back to chain?
Use the reverse factor: 1 nautical mile equals 92.06235584 chains. You can also use the swap control in the converter above to flip the direction instantly.
What is a chain?
Chain (ch) is a unit of length.
What is a nautical mile?
Nautical mile (nmi) measures distance. The international nautical mile is defined as exactly 1,852 meters, standardized in 1929. It is classified as a Non-SI unit accepted for use with SI (maritime/aviation).
Is the chain to nautical mile conversion exact?
Yes. The international nautical mile is defined as exactly 1,852 meters, standardized in 1929. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.