Length & Distance

Fathoms to Nautical Miles

Convert fathoms to nautical miles instantly. 1 ftm = 0.000987473 nmi. Includes the exact factor, a conversion table of common values and the definition of both units.

ftm
Nautical Miles

How to convert fathoms to nautical miles

To convert fathoms to nautical miles, divide by 1012.6859142607 (multiply by 0.000987473). The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.

nmi = ftm × 0.000987473

Fathoms to Nautical Miles conversion table

The values people look up most often, rounded for reading. Use the calculator above for anything in between.

FathomsNautical Miles
1 ftm0.0009875 nmi
2 ftm0.001975 nmi
3 ftm0.002962 nmi
5 ftm0.004937 nmi
10 ftm0.009875 nmi
20 ftm0.019749 nmi
25 ftm0.024687 nmi
50 ftm0.049374 nmi
100 ftm0.098747 nmi
500 ftm0.493737 nmi
1,000 ftm0.987473 nmi

What is a fathom?

Six feet. The traditional unit for water depth on nautical charts.

What is a nautical mile?

One minute of latitude, fixed at exactly 1,852 m. Used at sea and in the air.

The formula

nmi = ftm × 0.000987473

Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.

How to use the Fathoms to Nautical Miles

  1. Type the number of fathoms you want to convert.
  2. Read the result in nautical miles straight away — there is no button to press.
  3. Check the table below for the values that come up most often, or reverse the conversion with the linked nautical miles to fathoms page.

Fathoms to Nautical Miles — frequently asked questions

How many nautical miles are in a fathom?

One fathom equals 0.000987473 nmi. nmi = ftm × 0.000987473

What is the formula to convert fathoms to nautical miles?

The formula is nmi = ftm × 0.000987473. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.

How do I convert nautical miles back to fathoms?

Divide instead of multiplying: one nautical mile is 1012.6859142607 ftm. The reverse converter is linked in the related tools list.

Is this conversion exact?

Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.

Is this fathoms to nautical miles free to use?

Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.

What people search for

This page answers each of these searches. They are the exact phrases visitors use to find the fathoms to nautical miles.

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About this calculator

Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.

Last reviewed August 15, 2026 · Calculation runs client-side · No data collected · Report an error