Inches to Fathoms
Convert inches to fathoms instantly — one inch is 0.0138889 fathoms.
| Inches | Fathoms |
|---|---|
| 1 in | 0.013889 ftm |
| 2 in | 0.027778 ftm |
| 3 in | 0.041667 ftm |
| 5 in | 0.069444 ftm |
| 10 in | 0.138889 ftm |
| 25 in | 0.347222 ftm |
| 50 in | 0.694444 ftm |
| 100 in | 1.388889 ftm |
How to use
- Enter a value in the Inches field.
- The Fathoms figure appears immediately — no button to press.
- Typing in the Fathoms field converts back to Inches the same way.
- Use the reference table for the values that come up most often.
Inches to Fathoms formula
To convert inches to fathoms, multiply by 0.0138888889.
ftm = in × 0.0138888889
Put another way, one inch is exactly 1/72 of a fathom.
Why this factor: the inch and the fathom are both defined against the meter, so dividing one definition by the other gives 0.0138888889 directly. Both definitions are set out in full below.
To go the other way, divide by 0.0138888889 — or use the Fathoms to Inches converter, which is the same calculation reversed.
Worked example
Take 100 in and multiply by the factor 0.0138888889: the result is 1.388889 ftm.
100 in × 0.0138888889 = 1.388889 ftm
The converter above does this for any value you type, in either direction.
What is an inch?
An inch is one twelfth of a foot, used for small dimensions and for screen and wheel sizes globally.
Definition: Exactly 25.4 millimeters since the 1959 International Yard and Pound Agreement — an exact, not approximate, relation.
Where it is used: Screen diagonals, pipe and fastener sizes, tire and wheel diameters, and print layout worldwide.
What is a fathom?
A fathom is six feet, the traditional unit for water depth.
Definition: Six international feet, so exactly 1.8288 meters.
Where it is used: Nautical charts, depth soundings, and anchor and cable lengths.
Inches vs Fathoms
The inch is an imperial unit while the fathom is a specialized unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many fathoms are in an inch?
One inch equals 0.0138888889 fathoms.
What is the formula to convert inches to fathoms?
Multiply the number of inches by 0.0138888889. To reverse it, divide by 0.0138888889 instead.
How do I convert fathoms back to inches?
Divide by 0.0138888889, which is the same as multiplying by 72.
How many fathoms are in 10 inches?
10 in works out to 0.138889 ftm.
How is the inch defined?
Exactly 25.4 millimeters since the 1959 International Yard and Pound Agreement — an exact, not approximate, relation.