Convert Foot to Fathom

1 foot = 0.1666667 fathom (ftm). For example, 10 foot = 1.666667 fathom and 100 foot = 16.66667 fathom. Type any value below to convert foot to fathom both ways — it runs entirely in your browser.

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Quick answer: Foot to Fathom

1 Foot = 0.1666667 Fathom (ft → ftm). To convert foot to fathom, multiply by 0.1666667. To convert fathom to foot, multiply by 6. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common foot-to-fathom questions.

How to convert Foot to Fathom

To convert foot to fathom, multiply the number of foot by the conversion factor 0.1666667, because 1 ft = 0.1666667 ftm. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 ftm = 6 ft, so you divide by 0.1666667 (or multiply by 6) to turn fathom back into foot.

ftm = ft × 0.1666667  ·  ft = ftm × 6

  1. Write down the value you want to convert, in foot.
  2. Multiply it by 0.1666667.
  3. The result is the same area/length/quantity expressed in fathom.

Foot to Fathom — worked examples

Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 foot is 0.8333333 fathom because 5 ft × 0.1666667 = 0.8333333 ftm.

FootCalculationFathom
1 ft1 ft × 0.1666667 = 0.1666667 ftm0.1666667 ftm
2 ft2 ft × 0.1666667 = 0.3333333 ftm0.3333333 ftm
3 ft3 ft × 0.1666667 = 0.5 ftm0.5 ftm
5 ft5 ft × 0.1666667 = 0.8333333 ftm0.8333333 ftm
7 ft7 ft × 0.1666667 = 1.166667 ftm1.166667 ftm
10 ft10 ft × 0.1666667 = 1.666667 ftm1.666667 ftm
12 ft12 ft × 0.1666667 = 2 ftm2 ftm
15 ft15 ft × 0.1666667 = 2.5 ftm2.5 ftm
20 ft20 ft × 0.1666667 = 3.333333 ftm3.333333 ftm
25 ft25 ft × 0.1666667 = 4.166667 ftm4.166667 ftm
50 ft50 ft × 0.1666667 = 8.333333 ftm8.333333 ftm
100 ft100 ft × 0.1666667 = 16.66667 ftm16.66667 ftm

Common Foot to Fathom conversions

These are the foot-to-fathom values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:

  • 1 foot = 0.1666667 fathom
  • 2 foot = 0.3333333 fathom
  • 2.5 foot = 0.4166667 fathom
  • 3 foot = 0.5 fathom
  • 4 foot = 0.6666667 fathom
  • 5 foot = 0.8333333 fathom
  • 6 foot = 1 fathom
  • 7 foot = 1.166667 fathom
  • 8 foot = 1.333333 fathom
  • 9 foot = 1.5 fathom
  • 10 foot = 1.666667 fathom
  • 12 foot = 2 fathom
  • 15 foot = 2.5 fathom
  • 20 foot = 3.333333 fathom
  • 25 foot = 4.166667 fathom
  • 30 foot = 5 fathom
  • 50 foot = 8.333333 fathom
  • 75 foot = 12.5 fathom
  • 100 foot = 16.66667 fathom
  • 200 foot = 33.33333 fathom
  • 500 foot = 83.33333 fathom
  • 1000 foot = 166.6667 fathom

Foot to Fathom conversion chart (both directions)

The chart below converts foot to fathom and fathom to foot side by side, so it works whichever way you need. 1 foot = 0.1666667 fathom, and 1 fathom = 6 foot.

Foot → Fathom Fathom → Foot
0.25 ft = 0.04166667 ftm 0.25 ftm = 1.5 ft
0.5 ft = 0.08333333 ftm 0.5 ftm = 3 ft
1 ft = 0.1666667 ftm 1 ftm = 6 ft
2 ft = 0.3333333 ftm 2 ftm = 12 ft
3 ft = 0.5 ftm 3 ftm = 18 ft
4 ft = 0.6666667 ftm 4 ftm = 24 ft
5 ft = 0.8333333 ftm 5 ftm = 30 ft
6 ft = 1 ftm 6 ftm = 36 ft
7 ft = 1.166667 ftm 7 ftm = 42 ft
8 ft = 1.333333 ftm 8 ftm = 48 ft
9 ft = 1.5 ftm 9 ftm = 54 ft
10 ft = 1.666667 ftm 10 ftm = 60 ft
12 ft = 2 ftm 12 ftm = 72 ft
15 ft = 2.5 ftm 15 ftm = 90 ft
20 ft = 3.333333 ftm 20 ftm = 120 ft
25 ft = 4.166667 ftm 25 ftm = 150 ft
30 ft = 5 ftm 30 ftm = 180 ft
40 ft = 6.666667 ftm 40 ftm = 240 ft
50 ft = 8.333333 ftm 50 ftm = 300 ft
75 ft = 12.5 ftm 75 ftm = 450 ft
100 ft = 16.66667 ftm 100 ftm = 600 ft
150 ft = 25 ftm 150 ftm = 900 ft
200 ft = 33.33333 ftm 200 ftm = 1,200 ft
250 ft = 41.66667 ftm 250 ftm = 1,500 ft
500 ft = 83.33333 ftm 500 ftm = 3,000 ft
1000 ft = 166.6667 ftm 1000 ftm = 6,000 ft

Foot vs Fathom: which is bigger?

1 ft1 ftm
Relative size of 1 Foot (ft) and 1 Fathom (ftm).

A fathom is the larger unit: one fathom equals 6 foots. Put another way, you need 6 foots to make a single fathom.

What is a Foot? History, origin and usage

The foot is one of the most ancient units, based on the length of a human foot, and appeared in the Greek, Roman, Chinese and English systems with values ranging from about 250 to 335 mm. The English foot was eventually fixed at 12 inches, and since the 1959 international agreement it equals exactly 0.3048 metres.

The foot is still used in the US and UK for human height, building dimensions and, worldwide, aviation altitudes, since pilots almost everywhere report altitude in feet. It divides into 12 inches, and three feet make a yard.

Aircraft altitudes are measured in feet even in fully metric countries, a legacy of aviation's English-speaking origins. Historically the foot's length differed not only between countries but sometimes between trades within a single city.

What is a Fathom? History, origin and usage

The fathom comes from the Old English faedm, meaning 'outstretched arms' or 'embrace', because it was originally the span of a large man's arms held wide, about six feet. The word's deeper roots mean 'to spread', and from around 1600 'to fathom' also came to mean to take soundings, and figuratively to understand something fully.

The fathom is the traditional unit for water depth in seafaring and still appears on many nautical charts, though metres are now the standard. Six feet make one fathom.

The phrase 'to fathom' a problem comes directly from sailors measuring depth with a knotted, weighted line. Mark Twain took his pen name from the riverboat leadsman's call 'mark twain', meaning two fathoms of safe water.

Convert 1 Foot to other units

It can help to see a foot next to the other units it is commonly compared with. One foot (ft) is equal to:

1 Foot equalsUnit
0.0003048 kmKilometre
0.3048 mMetre
3.048 dmDecimetre
30.48 cmCentimetre
304.8 mmMillimetre
304,800 µmMicrometre
0.0001893939 miMile
0.3333333 ydYard
12 inInch
0.0001645788 nmiNautical Mile
0.001515152 furFurlong
0.01515152 chChain
1.515152 liLink
0.06060606 rdRod
0.06060606 polePole
0.1666667 ftmFathom
3 handHand
1.333333 spanSpan
2.666667 fingerFinger
0.6666667 cubitCubit
0.05 ropeRope
0.16764 kenKen
0.00006313131 leaLeague
864 ptPoint
2.0375e-12 AUAstronomical Unit
3.2217e-17 lyLight-year
0.03048 damDecametre
0.003048 hmHectometre
0.00005485961 nlNautical League

Convert 1 Fathom to other units

One fathom (ftm) is equal to:

1 Fathom equalsUnit
0.0018288 kmKilometre
1.8288 mMetre
18.288 dmDecimetre
182.88 cmCentimetre
1,828.8 mmMillimetre
1,828,800 µmMicrometre
0.001136364 miMile
2 ydYard
6 ftFoot
72 inInch
0.000987473 nmiNautical Mile
0.009090909 furFurlong
0.09090909 chChain
9.090909 liLink
0.3636364 rdRod
0.3636364 polePole
18 handHand
8 spanSpan
16 fingerFinger
4 cubitCubit
0.3 ropeRope
1.00584 kenKen
0.0003787879 leaLeague
5,184 ptPoint
1.2225e-11 AUAstronomical Unit
1.933e-16 lyLight-year
0.18288 damDecametre
0.018288 hmHectometre
0.0003291577 nlNautical League

Tips for converting Foot to Fathom

  • To go from foot to fathom, multiply by 0.1666667; to go back, divide by 0.1666667 (or multiply by 6).
  • For a quick mental estimate, remember that 1 foot ≈ 0.1666667 fathom, so 10 foot ≈ 1.666667 fathom.
  • The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
  • Both fields update live as you type — change either side to convert in that direction.

How to use this Foot to Fathom converter

Type a number into the Foot field and the equivalent in Fathom appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Fathom field to convert the other way (fathom to foot). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.

Accuracy and method

Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 ft = 0.1666667 ftm), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for foot-to-fathom conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.

The metric units (km, m, cm, mm, µm) are exact by definition, and the imperial units (mile, yard, foot, inch, nautical mile) use their exact international values. Traditional units (hand, span, finger, cubit, rod/pole, link, rope, ken, league) are given at their commonly accepted standard sizes — historical local values sometimes differed, so confirm against a primary source before relying on them for legal or historical work.

Frequently asked questions

How many fathom are in 1 foot?
1 foot = 0.1666667 fathom (ftm). To convert any number of foot to fathom, multiply by 0.1666667.
How do I convert foot to fathom?
Multiply the number of foot by 0.1666667. For example, 10 foot = 10 × 0.1666667 = 1.666667 fathom, and 25 foot = 4.166667 fathom.
How many foot are in 1 fathom?
1 fathom = 6 foot. So to convert fathom back to foot, multiply by 6.
What is the formula to convert foot to fathom?
fathom = foot × 0.1666667. The reverse formula is foot = fathom × 6.
How much is 100 foot in fathom?
100 foot = 16.66667 fathom. (And 1000 foot = 166.6667 fathom.)
Which is bigger, a foot or a fathom?
A fathom is larger: 1 fathom = 6 foot.
Is this foot to fathom converter accurate?
Yes — every value is computed from the exact 0.1666667 ftm per ft factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
Can I convert fathom to foot too?
Yes. The converter works both ways — enter a value in either field. 1 fathom = 6 foot.

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