How many fathoms are in 1 nautical mile?

One nautical mile contains approximately 1,012.69 fathoms.

How many nautical miles is 1 fathom?

One fathom equals approximately 0.000988 NM.

Why does maritime use NM for distance but fathoms for depth?

Historical convention. NM comes from latitude measurement (navigation). Fathoms come from leadline sounding (depth). Different tools, different units, same ocean.

Nautical Miles to Fathoms (nmi to ftm) Converter

1 nmi = 1,012.6859 ftm

1 Nautical Mile equals 1,012.6859 Fathoms (1 nmi = 1,012.6859 ftm). Convert Nautical Miles to Fathoms with formula, table, and examples.

One nautical mile equals approximately 1,012.69 fathoms. Both units serve maritime navigation: the NM measures horizontal distance across the ocean surface; the fathom measures vertical depth below it. They are perpendicular partners.

How to Convert Nautical Miles to Fathoms

ftm = nmi × 1,012.6859142607

Multiply the value in Nautical Miles by 1,012.6859142607

Take your value in Nautical Miles
Multiply by 1,012.6859142607
Read the result in Fathoms

Common Nautical Miles to Fathoms Conversions

Nautical Miles (nmi)	Fathoms (ftm)	Status
0.1 nmi	101.2686 ftm
0.5 nmi	506.343 ftm
1 nmi	1,012.6859 ftm
5 nmi	5,063.4296 ftm
10 nmi	10,126.8591 ftm
50 nmi	50,634.2957 ftm
100 nmi	101,268.5914 ftm
500 nmi	506,342.9571 ftm
1,000 nmi	1,012,685.9143 ftm
3,000 nmi	3,038,057.7428 ftm
10,000 nmi	10,126,859.1426 ftm
21,600 nmi	21,874,015.748 ftm

Good to Know About Nautical Miles to Fathoms Conversion

The NM and fathom are the ocean's x and y axes. One measures the horizontal surface; the other measures the vertical depth. Together they create a 2D coordinate system for nautical charts: position in NM, depth in fathoms. The ocean has its own measurement geometry.

Nautical Miles to Fathoms: What You Need to Know

1 NM is about 1,013 fathoms. The Mariana Trench at 6,011 fathoms is about 5.93 NM deep. Average ocean depth (2,024 fathoms) is about 2 NM. In nautical charts, NM scale the horizontal and fathoms scale the vertical.

What is a Nautical Mile? nmi

Exactly 1852 meters by international agreement. Based on one minute of arc of latitude at the Earth's surface. The standard unit for maritime and air navigation.

Nautical maritime navigation aviation international shipping

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What is a Fathom? ftm

Exactly 6 feet (1.8288 m). Traditionally used to measure water depth in nautical contexts. Originally based on the span of outstretched arms.

Imperial water depth nautical marine charts

Learn more about Fathom →

Going the other way? Use our Fathoms to Nautical Miles converter.

Nautical Miles to Fathoms FAQ

One nautical mile contains approximately 1,012.69 fathoms.
One fathom equals approximately 0.000988 NM.
Historical convention. NM comes from latitude measurement (navigation). Fathoms come from leadline sounding (depth). Different tools, different units, same ocean.

Non-Frequently Asked Questions About Nautical Miles to Fathoms

Questions nobody should ask - but someone did.

The Pacific is about 8,600 NM wide and about 5.93 NM (6,011 fathoms) deep. So the Pacific is about 1,450 times wider than deep. In the ocean's own units, it is a very thin puddle stretched across a very wide surface.
The Mariana Trench is 5.93 NM deep. At 20 knots: 5.93/20 = 0.297 hours = about 18 minutes. If ships could sail vertically, you could reach the deepest point in under 20 minutes. Horizontal oceans are days wide; vertical oceans are minutes deep.
Old sailing ships took depth soundings every few minutes. At 5 knots, that is about 1 sounding per 0.08 NM = about 81 fathom soundings per NM of travel. Each NM of forward progress came with 81 vertical measurements. Navigation was a horizontal-vertical dialogue.