Convert length and distance units — meters, feet, inches, kilometers, miles, light years and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 ftm | 9.87473e-07 nmi | |
| 0.01 ftm | 9.87473e-06 nmi | |
| 0.1 ftm | 9.87473e-05 nmi | |
| 1 ftm | 0.000987473 nmi | |
| 5 ftm | 0.00493737 nmi | |
| 10 ftm | 0.00987473 nmi | |
| 50 ftm | 0.0493737 nmi | |
| 100 ftm | 0.0987473 nmi | |
| 1000 ftm | 0.987473 nmi |
Multiply the number of Fathoms by 0.000987473 to get Nautical Miles. Formula: nmi = ftm × 0.000987473. Example: 10 ftm × 0.000987473 = 0.00987473 nmi. To reverse, divide Nautical Miles by 0.000987473 to get Fathoms.
| Fathom (ftm) | Nautical Mile (nmi) |
|---|---|
| 0.001 ftm | 9.87473e-07 nmi |
| 0.01 ftm | 9.87473e-06 nmi |
| 0.1 ftm | 9.87473e-05 nmi |
| 0.5 ftm | 0.000493737 nmi |
| 1 ftm | 0.000987473 nmi |
| 2 ftm | 0.00197495 nmi |
| 5 ftm | 0.00493737 nmi |
| 10 ftm | 0.00987473 nmi |
| 20 ftm | 0.0197495 nmi |
| 50 ftm | 0.0493737 nmi |
| 100 ftm | 0.0987473 nmi |
| 250 ftm | 0.246868 nmi |
| 500 ftm | 0.493737 nmi |
| 1000 ftm | 0.987473 nmi |
| 10000 ftm | 9.87473 nmi |
To convert Fathom to Nautical Mile, multiply by 0.000987473. Example: 10 ftm = 0.00987473 nmi
To convert Nautical Mile back to Fathom, divide by 0.000987473 (multiply by 1012.69). Use the swap button above.
Start with 100 Fathoms = 0.0987473 nmi as your reference point. Scale up or down from there.
Navigators reconciling depth soundings (fathoms on older charts) with horizontal distances (nautical miles) need to convert between the two units when calculating approach angles and under-keel clearance on shallow approaches.
Submarine navigators plot courses in nautical miles while managing depth in fathoms — both units are active simultaneously in submarine tactical operations. Converting between them is a standard naval navigation competency.
Fisheries authorities define exclusion zones in nautical miles while recording prohibited fishing depths in fathoms — regulations and enforcement documentation require cross-unit conversion.
Maritime historians reconstructing voyages from logbooks that record distances in nautical miles and depths in fathoms need cross-unit conversion to map routes and verify recorded water depth at historical anchorages.
Tidal stream atlases publish current speeds at specific positions (in nautical miles from reference points) and depths (in fathoms) — planners extracting data from these atlases convert between units for route planning software.
Dive operation planners using nautical charts express dive site positions in nautical miles from the vessel while planning descent to target depths expressed in fathoms on the chart — both units used simultaneously.
The Fathom is a unit of Length measurement (symbol: ftm). 1 ftm = 0.000987473 nmi. Used in scientific and practical Length measurement applications.
The Nautical Mile is a unit of Length measurement (symbol: nmi). It is part of an internationally recognised measurement system used alongside the Fathom.
The fathom derives from the Old English 'fæthm', meaning the span of outstretched arms — roughly 6 feet or 1.8 metres. It was the primary depth measurement unit used by mariners for millennia, recorded in the Bible and used by ancient Greeks. Samuel Pepys referenced fathoms in 17th-century naval logs. The word 'fathom' also entered English as a verb meaning to understand something deeply — from the idea of plumbing the depths. Despite metrication, fathoms remain on admiralty charts worldwide.
The nautical mile was defined by Earth's geography — one minute of arc of latitude along a meridian, approximately 1,852 metres. This made it ideal for navigation: on a nautical chart, one nautical mile equals one arcminute, allowing direct distance measurement with dividers. The International Hydrographic Conference standardised it at exactly 1,852 metres in 1929. It is universally used in maritime and aviation navigation — the only two domains that never adopted kilometres.
Common use: Fathom to Nautical Mile conversion is needed when working with international standards, scientific publications, or reference materials that use different unit systems for Length measurement.