Fathom to Nautical Mile Converter

Length Converter

31 units available

Decimals:

From

To

0.000987

1 ftm = 0.000987 nmi

Formula:

nmi = ftm × 0.000987473

With your value: 1 ftm = 0.00098747 nmi

How big is that?

Everyday references on a logarithmic scale, all expressed in fathom so you can sanity-check the result.

Credit card (long side) (1/21 your value)0.0468 ftm

A4 sheet (height) (1/6.2 your value)0.162 ftm

Adult stride (1/2.4 your value)0.410 ftm

Your value1.00 ftm

Standard door height (1.1× your value)1.09 ftm

London double-decker bus (6.0× your value)6.01 ftm

Other Fathom to Nautical Mile conversions

2 ftm to nmi 3 ftm to nmi 4 ftm to nmi 5 ftm to nmi 6 ftm to nmi 7 ftm to nmi 8 ftm to nmi

Fathom to Nautical Mile Conversion Table

Fathom (ftm)	Nautical Mile (nmi)
0.5	0.000494
1	0.000987
2	0.001975
5	0.004937
10	0.009875
15	0.014812
20	0.019749
25	0.024687
50	0.049374
100	0.098747
250	0.246868
500	0.493737
1000	0.987473

Nautical Mile to Fathom Conversion Table

Nautical Mile (nmi)	Fathom (ftm)
0.5	506.342957
1	1,012.685914
2	2,025.371829
5	5,063.429571
10	10,126.859143
15	15,190.288714
20	20,253.718285
25	25,317.147857
50	50,634.295713
100	101,268.591426
250	253,171.478565
500	506,342.95713
1000	1,012,685.914261

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Fathom (ftm)

Length

Exact conversion

Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

Nautical Mile (nmi)

Length

Conventional value

1 international nautical mile = 1852 m exactly, adopted by the First International Extraordinary Hydrographic Conference (1929).

Source: Units accepted for use with the SI, SI Brochure Table 8

Bureau International des Poids et Mesures · Reviewed 2026-07-01

How to Convert Fathom to Nautical Mile

To convert from Fathom (ftm) to Nautical Mile (nmi), multiply the value by 0.000987473.

Formula: nmi = ftm × 0.000987473

Reverse: ftm = nmi × 1,012.6859142607

Step-by-Step Example

Start with your value in Fathom. For example: 5 ftm
Multiply by the conversion factor: 5 x 0.000987473
The result is: 0.004937 nmi

About Fathom

The fathom equals 6 feet (1.8288 m) and is the traditional unit for water depth on nautical charts.

Fun Fact: The word comes from the Old English "fæðm", the span of a man's outstretched arms.

Common uses: sounding depth, nautical charts, diving.

About Nautical Mile

The nautical mile equals 1,852 meters and is used primarily in aviation and maritime navigation.

Fun Fact: One nautical mile corresponds to one minute of latitude on the Earth's surface.

Common uses: navigation, aviation, maritime.

Frequently Asked Questions

How many Nautical Mile are in 1 Fathom?

There are exactly 0.000987473 Nautical Mile in 1 Fathom. This means the conversion factor from Fathom to Nautical Mile is 0.000987473.

What is the formula to convert Fathom to Nautical Mile?

The formula to convert Fathom to Nautical Mile is: nmi = ftm × 0.000987473. For example, to convert 10 Fathom to Nautical Mile, you would multiply 10 by 0.000987473.

What is a Fathom?