Convert Foot to Fathom (ft → ftm)
The foot is the standard unit for human height, building floor counts, and aviation altitudes worldwide.
Foot to Fathom Conversion Table
10 common values| Foot | Fathom |
|---|---|
| 1 ft | 0.166667 ftm |
| 5 ft | 0.833333 ftm |
| 10 ft | 1.666667 ftm |
| 25 ft | 4.166667 ftm |
| 50 ft | 8.333333 ftm |
| 100 ft | 16.666667 ftm |
| 250 ft | 41.666667 ftm |
| 500 ft | 83.333333 ftm |
| 1,000 ft | 166.66667 ftm |
| 5,000 ft | 833.33333 ftm |
How to Convert Foot to Fathom Manually
Step by StepConverting feet to fathoms is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.
- 1Take your value in feetStart with the number of feet (ft) you want to convert.
- 2Multiply by 0.166667The conversion factor from ft to ftm is 0.166667. Multiply your value by this number.
- 3Read the result in fathomsThe result is your value in fathoms (ftm).
Formula
Multiply the value in feet by 0.166667. For the reverse direction, multiply by 6.
ftm = ft × 0.166667ft = ftm × 6Tips
Use these in everyday conversions- 1 foot = 12 inches = 30.48 cm exactly. Knowing feet gives you inches instantly.
- For a quick metric estimate, multiply feet by 0.3 — 10 ft ≈ 3 m.
- Pilots and air-traffic control use feet globally, even over metric countries.
Common Mistakes
Avoid these- Writing "6.2 ft" to mean "6 feet 2 inches" — the decimal form is 6.167 ft, not 6.2.
- Confusing feet (length) with square feet (area) in US real-estate listings.
- Using 0.3 instead of 0.3048 on structural drawings — errors accumulate on multi-storey buildings.
About Foot and Fathom
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).
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.