Nautical Mile to Fathom Conversion Calculator: Free Online Tool

Convert nautical miles to fathoms with our free online length converter.

Nautical Mile to Fathom Calculator

Nautical Mile
Fathom

How to Use the Calculator:

  1. Enter the value you want to convert in the 'From' field (Nautical Mile).
  2. The converted value in Fathom will appear automatically in the 'To' field.
  3. Use the dropdown menus to select different units within the Length category.
  4. Click the swap button (⇌) to reverse the conversion direction.

How to Convert Nautical Mile to Fathom

Converting Nautical Mile to Fathom involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Nautical Mile = 1012.686 fathoms

Example Calculation:

Convert 10 nautical miles: 10 × 1012.686 = 1.0127e+4 fathoms

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

What is a Nautical Mile and a Fathom?

A nautical mile is a unit of length used in marine and air navigation. It is defined as exactly 1,852 meters.

The Fathom (symbol fath) is a unit of length in the imperial and U.S. customary systems of measurement, defined as exactly 6 feet (ft). This is equivalent to 2 yards or 1.8288 meters (m). It is almost exclusively used in maritime contexts for measuring the depth of water.

Note: The Nautical Mile is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Fathom belongs to the imperial/US customary system.

History of the Nautical Mile and Fathom

The nautical mile originated from the length of one minute of arc of latitude along any meridian. It was standardized internationally in 1929.

The word "fathom" originates from the Old English word fæthm, meaning "a pair of outstretched arms" or "embrace". Historically, the length was derived from the distance between the fingertips of a man's outstretched arms, a practical method for sailors measuring the length of a sounding line (a rope with a weight used to measure water depth) as they hauled it in. This naturally variable measure was eventually standardized to precisely 6 feet. For centuries, it was the primary unit for depth soundings on nautical charts and in maritime operations in English-speaking countries and beyond. While its official use has declined with metrication, it remains a significant unit in nautical tradition.

Common Uses for nautical miles and fathoms

Explore the typical applications for both Nautical Mile (imperial/US) and Fathom (imperial/US) to understand their common contexts.

Common Uses for nautical miles

  • Marine navigation
  • Air navigation
  • Charting distances over water or air

Common Uses for fathoms

The fathom's use is strongly tied to the sea:

  • Hydrography & Navigation: Measuring water depth (soundings) on nautical charts. Many charts, particularly older ones or those used in the US and UK, still use fathoms. Contour lines showing seabed depth are often called "fathom lines".
  • Nautical Terminology: Used historically to measure the length of ropes and anchor cables (e.g., a "cable length" was often defined as 100 or 120 fathoms).
  • Commercial Fishing: Sometimes used by fishermen to describe the length of nets or fishing lines, or the depth at which they are fishing.
  • Literature & Figurative Language: Frequently appears in maritime literature (e.g., "full fathom five" from Shakespeare's The Tempest). Metaphorically, "to fathom" means to comprehend or get to the bottom of something complex.
  • Historical Land Measurement: Very occasionally used in historical land surveying or mining contexts, but this was rare compared to its maritime use.

Frequently Asked Questions

Questions About Nautical Mile (NM)

Why is a nautical mile different from a statute mile?

A statute mile (used on land, 1609.344 meters) is based on historical measurements. A nautical mile (1852 meters) is derived from the Earth's circumference (1 minute of latitude) and simplifies navigation calculations.

How many feet are in a nautical mile?

One nautical mile is approximately 6076.115 feet.

What is a knot in relation to a nautical mile?

A knot is a unit of speed equal to one nautical mile per hour. It's commonly used in maritime and aviation contexts.

About Fathom (fath)

How many feet are in a fathom?

There are exactly 6 feet (ft) in 1 fathom.

How many meters are in a fathom?

One fathom is equal to exactly 1.8288 meters (m).

Is the fathom an SI unit?

No, the fathom is not an SI unit. It is part of the imperial and U.S. customary systems. The corresponding SI unit for length is the meter (m).

Is the fathom still commonly used today?

Its usage has decreased significantly due to the widespread adoption of the metric system in international shipping and hydrography. However, it remains common on nautical charts produced by countries like the United States and the United Kingdom, and it persists in recreational boating, commercial fishing communities, maritime tradition, and literature. Modern international charts increasingly use meters for depth soundings.

Where does the word 'fathom' come from?

The word originates from the Old English fæthm, which referred to the span of a person's outstretched arms. This distance was the practical basis for the original measurement used by sailors.

Conversion Table: Nautical Mile to Fathom

Nautical Mile (NM)Fathom (fath)
11,012.686
55,063.43
1010,126.859
2525,317.148
5050,634.296
100101,268.591
500506,342.957
1,0001,012,685.914

All Length Conversions

Meter to KilometerMeter to HectometerMeter to DecimeterMeter to CentimeterMeter to MillimeterMeter to InchMeter to FootMeter to YardMeter to MileMeter to Nautical MileMeter to MicrometerMeter to NanometerMeter to Light YearMeter to Astronomical UnitMeter to ParsecMeter to AngstromMeter to Point (Typography)Meter to Mil/ThouMeter to FathomMeter to FurlongMeter to Link (Gunter's)Meter to PaceMeter to SpanMeter to DigitMeter to Cable LengthMeter to EllMeter to FingerMeter to Roman MileMeter to StadionMeter to Chi (Chinese)Meter to Shaku (Japanese)Meter to Li (Chinese)Meter to ToiseMeter to BoltMeter to RopeMeter to SmootMeter to SajeneMeter to KenMeter to WaMeter to VaraMeter to AlnMeter to Cubit (Royal/Egyptian)Meter to VerstaMeter to ArpentMeter to Ri (Japanese)Meter to KlafterMeter to YojanaMeter to SkeinKilometer to MeterKilometer to HectometerKilometer to DecimeterKilometer to CentimeterKilometer to MillimeterKilometer to InchKilometer to FootKilometer to YardKilometer to MileKilometer to Nautical MileKilometer to MicrometerKilometer to NanometerKilometer to Light YearKilometer to Astronomical UnitKilometer to ParsecKilometer to AngstromKilometer to Point (Typography)Kilometer to Mil/ThouKilometer to FathomKilometer to FurlongKilometer to Link (Gunter's)Kilometer to PaceKilometer to SpanKilometer to DigitKilometer to Cable LengthKilometer to EllKilometer to FingerKilometer to Roman MileKilometer to StadionKilometer to Chi (Chinese)Kilometer to Shaku (Japanese)Kilometer to Li (Chinese)Kilometer to ToiseKilometer to BoltKilometer to RopeKilometer to SmootKilometer to SajeneKilometer to KenKilometer to WaKilometer to VaraKilometer to AlnKilometer to Cubit (Royal/Egyptian)Kilometer to VerstaKilometer to ArpentKilometer to Ri (Japanese)Kilometer to KlafterKilometer to YojanaKilometer to SkeinHectometer to MeterHectometer to KilometerHectometer to DecimeterHectometer to CentimeterHectometer to MillimeterHectometer to InchHectometer to FootHectometer to YardHectometer to MileHectometer to Nautical MileHectometer to MicrometerHectometer to NanometerHectometer to Light YearHectometer to Astronomical UnitHectometer to ParsecHectometer to AngstromHectometer to Point (Typography)Hectometer to Mil/ThouHectometer to FathomHectometer to FurlongHectometer to Link (Gunter's)Hectometer to PaceHectometer to SpanHectometer to Digit