Convert Fathom to Foot (ftm → ft)
The fathom is the traditional marine depth unit, equal to six feet, used in nautical charts and diving manuals.
Fathom to Foot Conversion Table
10 common values| Fathom | Foot |
|---|---|
| 1 ftm | 6 ft |
| 5 ftm | 30 ft |
| 10 ftm | 60 ft |
| 25 ftm | 150 ft |
| 50 ftm | 300 ft |
| 100 ftm | 600 ft |
| 250 ftm | 1,500 ft |
| 500 ftm | 3,000 ft |
| 1,000 ftm | 6,000 ft |
| 5,000 ftm | 30,000 ft |
How to Convert Fathom to Foot Manually
Step by StepConverting fathoms to feet is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.
- 1Take your value in fathomsStart with the number of fathoms (ftm) you want to convert.
- 2Multiply by 6The conversion factor from ftm to ft is 6. Multiply your value by this number.
- 3Read the result in feetThe result is your value in feet (ft).
Formula
Multiply the value in fathoms by 6. For the reverse direction, multiply by 0.166667.
ft = ftm × 6ftm = ft × 0.166667Tips
Use these in everyday conversions- 1 fathom = 2 yards = 6 feet = 1.8288 m.
- Modern charts use metres internationally; fathoms are mostly historical.
- The word "fathom" comes from Old English for "outstretched arms" — originally the span of an adult's arms.
Common Mistakes
Avoid these- Reading a modern chart that uses metres as if it were fathoms — a factor-of-1.83 depth error.
- Confusing fathoms with feet on mixed-unit charts.
- Assuming all US charts still use fathoms — NOAA has largely migrated to metres.
About Fathom and Foot
What is the Fathom?
The fathom equals exactly 1.8288 meters or 6 feet and is the traditional marine depth unit. The word derives from the Old English 'fæðm,' meaning the span of outstretched arms — historically the distance a sailor could measure rope by stretching it from fingertip to fingertip. Used since antiquity for sounding water depth (lowering a weighted line and counting fathom marks), the fathom remains common in nautical charts, diving manuals, and marine literature. Famous from Mark Twain's pen name (a riverboat lead's call meaning 'safe water,' 2 fathoms or 12 feet) and Shakespeare's 'full fathom five,' the unit retains cultural resonance. Modern oceanographic science prefers the meter, but the fathom persists in fishing, recreational diving, and historical maritime contexts. The fathom relates to the foot (1 fathom = 6 ft) and the yard (1 fathom = 2 yd).
- Water depth on older US nautical charts
- Maritime literature and historical navigation
- Sport diving and scuba depth references in the US
A "mark twain" reading — made famous by the Mississippi riverboats — meant 2 fathoms (3.66 m) of water, the minimum safe depth.
What is the Foot?
The foot equals exactly 0.3048 meters or 12 inches under the 1959 international agreement. The unit's name reflects its ancient origin as the length of an adult human foot, with measurements varying by region — from 250 mm to over 330 mm — until standardization. The foot is the dominant unit for human height in the United States and the United Kingdom (a person is described as '5 ft 10 in' rather than 178 cm), for building heights, and for aviation altitudes (worldwide aircraft fly at altitudes given in feet, even in metric countries). It remains the standard for residential floor counts, ceiling heights, and ladder ratings. The foot relates to the meter (1 ft ≈ 0.305 m), the yard (3 ft = 1 yd), and the mile (5,280 ft = 1 mi).
- Aircraft cruising altitude in international aviation
- US building heights, ceiling heights and room dimensions
- Mountain elevations on global maps (Everest = 29,032 ft)
Airliners cruise at 35,000 ft (10.7 km). Mount Everest is 29,032 ft (8,849 m). A standard US ceiling is 8 ft (2.44 m).