Convert nautical miles to fathoms

1 nmi=1,012.69ftm

Use the converter below to change any nautical miles value into fathoms instantly — with formula, conversion table, and real-world examples.

You have

Equals

1,012.69

Conversion formula

Forward

fathoms = nautical miles × 1,012.69

Reverse

nautical miles = fathoms × 0.0009875

Example: 10 nmi × 1,012.69 = 10,126.86 ftm.

About both units

From

Nautical Mile

nmi

The nautical mile equals 1852 meters exactly — defined as one minute of arc along a meridian. It is the standard distance unit for marine and air navigation worldwide. Ship and aircraft speeds are given in knots, where 1 knot = 1 nautical mile per hour.

Real-world: Territorial waters extend 12 nautical miles from the coastline. London Heathrow to New York JFK is about 3000 nmi.

Read full nautical mile reference →

Fathom

ftm

The fathom equals exactly 6 feet or 1.8288 meters. It is the traditional marine unit for water depth, used on older nautical charts and in recreational sailing. Modern charts mark depths in metres, but fathoms still appear in maritime literature and older US charts.

Real-world: A "mark twain" reading — made famous by the Mississippi riverboats — meant 2 fathoms (3.66 m) of water, the minimum safe depth.

Read full fathom reference →

Nautical Mile to Fathom conversion table

Common nautical miles to fathoms values for quick reference.

Nautical Mile (nmi)	Fathom (ftm)
1 nmi	1,012.69 ftm
5 nmi	5,063.43 ftm
10 nmi	10,126.86 ftm
25 nmi	25,317.15 ftm
50 nmi	50,634.3 ftm
100 nmi	101,268.59 ftm
250 nmi	253,171.48 ftm
500 nmi	506,342.96 ftm
1,000 nmi	1,012,685.91 ftm
5,000 nmi	5,063,429.57 ftm

Tips & common mistakes

Quick tips

1 nautical mile = 1.852 km = 1.151 statute miles.
A knot (1 nmi/h) equals 1.852 km/h — remember this for weather and sailing reports.
Latitude is measured in degrees and minutes; one minute of latitude equals exactly one nautical mile.

Avoid these

Confusing nautical miles with statute miles — the 15% difference matters in flight planning.
Reading knots as km/h on weather reports — a 40-knot wind is 74 km/h, not 40.
Using nautical miles on land — outside navigation contexts, use kilometres or statute miles.

Frequently asked questions

How many fathoms in a nautical mile?

One nautical mile equals 1,012.69 fathoms.

How do I convert nautical miles to fathoms?

Multiply the nautical mile value by 1,012.69 to get the equivalent in fathoms.

What is 100 nautical miles in fathoms?

100 nautical miles equals 101,268.59 fathoms.

Is a nautical mile bigger than a fathom?

Yes. 1 nautical mile equals 1,012.69 fathoms, so one nautical mile is larger.

How to convert nautical miles to fathoms without a calculator?

Multiply by 1,012.69 for a quick estimate; use a calculator for precise results.

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