Convert Fathom to Kilometer (ftm → km)

Converting fathoms to kilometers is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in fathoms

   Start with the number of fathoms (ftm) you want to convert.
2. 2
   Multiply by 0.001829

   The conversion factor from ftm to km is 0.001829. Multiply your value by this number.
3. 3
   Read the result in kilometers

   The result is your value in kilometers (km).

Multiply the value in fathoms by 0.001829. For the reverse direction, multiply by 546.80665.

• ✓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.

• ✗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.

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

What is the Kilometer?

The kilometer equals exactly 1,000 meters and is the international standard unit for road distances, geography, and travel. Adopted as part of the metric system in the 1790s, it became the dominant road-distance unit worldwide except in the United States, the United Kingdom (which uses miles for road signs), and Myanmar. Speed limits across Europe, Asia, Australia, Africa, and Latin America are expressed in km/h. The kilometer's relationship to the meter is decimal and exact, making it ideal for scientific work. A kilometer takes a healthy adult about 12 minutes to walk and roughly 1,250 average steps. Geographic distances — from city blocks to airline routes — are typically given in kilometers, with the Earth's equatorial circumference measuring approximately 40,075 km.

• Motorway distances on road signs across Europe
• Marathon and long-distance running (marathon = 42.195 km)
• GPS navigation and driving directions globally