Convert Fathom to Inch
Convert fathoms to inches instantly. 1 fathom = 72 inch — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Inch to Fathom converter for the reverse conversion.
Units explained
Fathom
A fathom is an Imperial unit of length equal to 6 feet or exactly 1.8288 meters. It is used almost exclusively for measuring water depth in maritime contexts.
The fathom derives from the Old English word fæthm, meaning "the embracing arms" — the distance between the fingertips of a person's outstretched arms. Standardized at 6 feet in English maritime tradition.
Fathoms are used in nautical depth charts, scuba diving, oceanography, and maritime literature. Despite metrication efforts, fathoms remain common in English-language nautical charts and recreational diving.
Old English origin (predating 1066); standardized at 6 feet by English maritime tradition; fixed at 1.8288 m exactly via the 1959 International Yard and Pound Agreement.
Inch
An inch is an Imperial and US customary unit of length defined since 1959 as exactly 25.4 millimeters (0.0254 meters). It is still the standard small unit of length in the United States, the United Kingdom (informally), and a few other countries.
The inch derives from the Roman uncia (one-twelfth of a foot) and survived through Anglo-Saxon and medieval English measurement systems. Various definitions persisted regionally until the 1959 International Yard and Pound Agreement standardized the inch globally as exactly 25.4 mm.
Inches are used in the US and UK for body height, screen sizes (TVs, monitors, phones), tire sizes, plumbing, lumber, paper sizes (US Letter is 8.5 × 11 in), and most consumer product specifications in the United States.
Anglo-Saxon origin (predating 1066); standardized to 25.4 mm exactly by the International Yard and Pound Agreement of 1959, signed by the US, UK, Canada, Australia, New Zealand, and South Africa.
Fathom to Inch conversion formula
The relationship between fathoms and inches:
To convert fathoms to inches, multiply the value in fathoms by 72. To reverse, multiply inches by 0.0138888889.
How to use this converter
Type a value into the calculator. The result in inches updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Inch to Fathom converter for the reverse direction.
Step-by-step: convert fathoms to inches
- Write down the value in fathoms (ftm).
- Multiply that value by the factor 72.
- The product is the equivalent value in inches (in).
- To reverse, multiply the inch value by 0.0138888889.
Worked examples
Example 1 — Convert 1 ftm to in:
1 × 72 = 72 in
Example 2 — Convert 100 ftm to in:
100 × 72 = 7200 in
Real-world example — Pet and accessory dimensions
A 3-fathom dog leash equals a tidy round value in inches. Pet-supply shopping frequently mixes the two units across product specifications.
3 ftm × 72 = 216 in
Real-world example — Fabric and tailoring
One fathom of fabric converts to a value in inches commonly used for seam allowances. Garment patterns frequently switch between the two units on a single instruction sheet.
1 ftm × 72 = 72 in
Real-world example — Body height conversion (reverse direction)
You measure 1.75 fathoms tall and need to fill in a gym membership form or medical record that asks for height in inches. This is the most-used everyday length conversion in metric-using countries.
1.75 ftm × 72 = 126 in
Fathom to Inch conversion table
Standard reference values for converting fathoms to inches:
| Fathom [ftm] | Inch [in] |
|---|---|
| 0.01 | 0.72 |
| 0.1 | 7.2 |
| 1 | 72 |
| 2 | 144 |
| 3 | 216 |
| 4 | 288 |
| 5 | 360 |
| 10 | 720 |
| 20 | 1440 |
| 30 | 2160 |
| 40 | 2880 |
| 50 | 3600 |
| 100 | 7200 |
| 500 | 36000 |
| 1000 | 72000 |
Frequently asked questions
How many inches is 1 fathom?
How do I convert fathoms to inches?
How do I convert inches back to fathoms?
How many inches is 100 fathoms?
Popular length unit conversions
Convert Fathom to other length units
Show all Fathom conversions
Metric / SI (7 units)
Imperial / US Customary (26 units)
Nautical (1 units)
Sources & references
Conversion factor (1 ftm = 72 in) 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.