Why do ships use nautical miles instead of kilometers?

Because 1 NM = 1 minute of latitude, distances can be read directly from a chart's latitude scale. This relationship makes dead reckoning and celestial navigation practical at sea.

How long is a nautical mile vs a regular mile?

1 NM = 1.15078 statute miles. A nautical mile is about 15% longer than a land mile.

What is a cable length?

A cable is 1/10 of a nautical mile, or 185.2 meters. It is used for short maritime distances, especially in harbors and anchorages.

How many nautical miles in a degree of latitude?

Approximately 60 NM per degree of latitude. This varies slightly due to Earth's equatorial bulge.

Do aircraft use nautical miles?

Yes. International aviation exclusively uses nautical miles for distance and knots (NM/hour) for airspeed, regardless of the country.

A fathom is 6 feet (1.8288 m), historically used for measuring water depth. There are about 1,012.7 fathoms in one nautical mile.

Nautical Miles Converter

Convert nautical miles to kilometers, statute miles, meters, feet, cables, and fathoms. Includes maritime distance context table and batch mode.

Nautical Mile Converter

From Unit

Value

To Unit

Precision

Nautical Miles

1.0000

1 NM = 1,852 m exactly

Kilometers

1.8520

1 NM = 1.852 km

Statute Miles

1.1508

1 NM ≈ 1.15078 mi

Meters

1,852.0000

1 NM = 1,852 m

Feet

6,076.1155

1 NM = 6,076.12 ft

Latitude Minutes

1.0000

1 NM = 1 minute of latitude

Cables

10.0000

1 cable = 1/10 NM = 185.2 m

Nautical Distance Context

NM	km	mi	Context
0.1	0.2	0.1	1 cable length
1.0	1.9	1.2	1 minute of latitude
3.0	5.6	3.5	Typical harbor to anchorage
12.0	22.2	13.8	Territorial waters limit
24.0	44.4	27.6	Contiguous zone
60.0	111.1	69.0	1 degree of latitude
200.0	370.4	230.2	Exclusive economic zone
500.0	926.0	575.4	Typical overnight sail
2,160.0	4,000.3	2,485.7	Transatlantic crossing (shortest)
8,500.0	15,742.0	9,781.6	Transpacific crossing

Batch Conversion

Multiple values (comma/newline separated)

Planning notes, formulas, and examples

About the Nautical Miles Converter

The nautical mile (NM) is the standard distance unit in maritime and aviation navigation worldwide. Defined as exactly 1,852 meters by international agreement, one nautical mile corresponds to one minute of latitude — a relationship that makes it uniquely practical for navigation on a spherical Earth.

Converting between nautical miles and land-based units (kilometers, statute miles, feet) is essential for anyone crossing between maritime/aviation and terrestrial contexts: coast guards, pilots, sailors, marine engineers, and fishermen all need these conversions regularly. The nautical mile is about 15% longer than a statute mile (1 NM ≈ 1.151 mi) and about 85% longer than a kilometer (1 NM = 1.852 km).

This converter handles eight units including cables (1/10 NM, used for harbor distances) and fathoms (6 feet, used for depth), shows latitude-minute equivalences, and provides a context table spanning from harbor distances to transoceanic crossings.

When This Page Helps

Use this converter when you need to move between navigation units and land-based distance units without losing the maritime context. It is especially useful when a route, legal zone, or speed calculation is written in nautical miles but the surrounding discussion uses kilometers, statute miles, or feet.

How to Use the Inputs

Select your input unit (nautical miles, km, miles, meters, feet, cables, fathoms).
Enter a distance or click a preset for common maritime distances.
Choose your target output unit.
Set decimal precision for your application.
Read the primary result plus seven simultaneous outputs including latitude minutes.
Consult the context table for maritime distance benchmarks.
Use batch mode to convert multiple distances at once.

Formula used

1 Nautical Mile = 1,852 meters (exact, by international agreement)
1 NM = 1.852 km = 1.15078 statute miles = 6,076.12 feet
1 NM = 1 minute of latitude = 10 cables = 1,012.68 fathoms

Example Calculation

Result: 22.224 km

12 NM × 1.852 = 22.224 km. This is the internationally recognized extent of territorial waters.

Tips & Best Practices

Quick estimate: NM × 1.85 ≈ km, or NM × 1.15 ≈ statute miles.
On a navigation chart, latitude tick marks on the side of the chart directly represent nautical miles — longitude tick marks do not (they vary with latitude).
Territorial waters extend 12 NM from shore; the exclusive economic zone extends 200 NM.
For speed: 1 knot = 1 NM/hour. So 10 knots for 5 hours = 50 NM.
Fathoms for depth and cables for distance are still used in many navies and merchant fleets.

History of the Nautical Mile

The concept dates to the 17th century, when navigators realized that tying distance to latitude made chart work much simpler. Various countries defined the nautical mile slightly differently until 1929, when the International Hydrographic Organization adopted 1,852 m as the standard. The US didn't adopt this definition until 1954.

Maritime Legal Zones

| Zone | Distance from shore | Significance | |---|---|---| | Territorial Sea | 12 NM | Full sovereignty | | Contiguous Zone | 24 NM | Customs and immigration enforcement | | Exclusive Economic Zone | 200 NM | Fishing and resource rights | | Continental Shelf | Up to 350 NM | Seabed resource rights |

Aviation Use

All international flight plans, airway distances, and instrument approach procedures use nautical miles. A standard holding pattern is 1 NM per leg. Visibility is reported in statute miles in the US but in meters/km internationally. Altitude is always in feet. This mix of units makes reliable conversion tools essential for pilots and dispatchers.

Sources & Methodology

Last updated: March 8, 2026

Frequently Asked Questions

Because 1 NM = 1 minute of latitude, distances can be read directly from a chart's latitude scale. This relationship makes dead reckoning and celestial navigation practical at sea.