How many chains is 1 fathom?

One fathom equals exactly 1/11 of a chain (approximately 0.09091 chains). Eleven fathoms make exactly one chain.

How many fathoms are in 1 chain?

One chain contains exactly 11 fathoms. Both are defined in feet: 1 chain = 66 feet, 1 fathom = 6 feet, 66/6 = 11.

Why is the ratio exactly 11?

Because both units are defined as exact multiples of the foot. The chain is 66 feet, the fathom is 6 feet. 66 divided by 6 equals exactly 11. This clean ratio is a rarity in the imperial system.

Fathoms to Chains (ftm to ch) Converter

1 ftm = 0.0909 ch

1 Fathom equals 0.0909 Chains (1 ftm = 0.0909 ch). Convert Fathoms to Chains with formula, table, and examples.

One fathom equals exactly 1/11 of a chain, or approximately 0.09091 chains. Conversely, one chain (66 feet) contains exactly 11 fathoms (66/6 = 11). Both units derive from the English foot-based measurement system, but the fathom measures depth at sea while the chain measures distance on land.

How to Convert Fathoms to Chains

ch = ftm ÷ 11

Divide the value in Fathoms by 11

Take your value in Fathoms
Divide by 11
Read the result in Chains

Common Fathoms to Chains Conversions

Fathoms (ftm)	Chains (ch)	Status
0.5 ftm	0.0455 ch
1 ftm	0.0909 ch
2 ftm	0.1818 ch
5 ftm	0.4545 ch
10 ftm	0.9091 ch
11 ftm	1 ch
20 ftm	1.8182 ch
50 ftm	4.5455 ch
100 ftm	9.0909 ch
200 ftm	18.1818 ch
500 ftm	45.4545 ch
1,000 ftm	90.9091 ch
6,000 ftm	545.4545 ch

Good to Know About Fathoms to Chains Conversion

The fathom and chain both descend from the English foot but diverged into sea and land. Sailors measured rope in fathoms; surveyors measured fields in chains. The 11:1 ratio is a remnant of their shared ancestry in the foot-based system.

Fathoms to Chains: What You Need to Know

Eleven fathoms make one chain. One furlong (10 chains) equals 110 fathoms. One mile (80 chains) equals 880 fathoms. The clean 11:1 ratio exists because both units are exact multiples of the foot: 6 feet per fathom, 66 feet per chain, and 66/6 = 11.

What is a Fathom? ftm

Exactly 6 feet (1.8288 m). Traditionally used to measure water depth in nautical contexts. Originally based on the span of outstretched arms.

Imperial water depth nautical marine charts

Learn more about Fathom →

What is a Chain? ch

Exactly 66 feet or 4 rods (20.1168 m). Invented by Edmund Gunter for land surveying. 80 chains make one mile. Still used in US public land surveys.

Imperial land surveying US public land

Learn more about Chain →

Going the other way? Use our Chains to Fathoms converter.

Fathoms to Chains FAQ

One fathom equals exactly 1/11 of a chain (approximately 0.09091 chains). Eleven fathoms make exactly one chain.
One chain contains exactly 11 fathoms. Both are defined in feet: 1 chain = 66 feet, 1 fathom = 6 feet, 66/6 = 11.
Because both units are defined as exact multiples of the foot. The chain is 66 feet, the fathom is 6 feet. 66 divided by 6 equals exactly 11. This clean ratio is a rarity in the imperial system.

Non-Frequently Asked Questions About Fathoms to Chains

Questions nobody should ask - but someone did.

A chain (66 feet) is about 3.6 times longer than a fathom (6 feet). But anchor chain measured in fathoms can be hundreds of fathoms long, while a field might be only 10-20 chains. In total length, the anchor chain usually wins. The ocean is bigger than most fields.
Not surveyor's chains. But anchor chains (measured in nautical fathom-based 'shackles') serve a similar function underwater as surveyor's chains did on land: measuring known lengths of something. Both professions count chain links for a living.
Modern ocean floor surveys use meters. Historically, depth used fathoms and horizontal distance used whatever the ship's navigation offered. Nobody dragged a Gunter's chain across the seabed. The barnacles alone would make it impossible.