Nautical miles to kilometres
A nautical mile (NM) is exactly 1852 metres, that is 1.852 km. Type a distance and the converter gives you kilometres, cables, statute miles, yards, feet and fathoms side by side.
Quick try:
The cable here is the international one, 0.1 NM (185.2 m); the US Navy counted 219.5 m and the Royal Navy 185.3 m. A shackle of anchor chain is 15 fathoms (27.43 m).
Common distances converted
| NM | km | mi | cbl |
|---|---|---|---|
| 1 | 1.852 | 1.150779 | 10 |
| 2 | 3.704 | 2.301559 | 20 |
| 5 | 9.26 | 5.753897 | 50 |
| 10 | 18.52 | 11.50779 | 100 |
| 20 | 37.04 | 23.01559 | 200 |
| 50 | 92.6 | 57.53897 | 500 |
| 100 | 185.2 | 115.0779 | 1,000 |
| 500 | 926 | 575.3897 | 5,000 |
Values computed from the exact definitions of the units (NIST SP 811 and the international agreements), rounded to 7 significant digits. The first column is nautical miles.
Why exactly 1852 metres
A nautical mile matches one minute of arc of a meridian, that is one minute of latitude. The Earth is not a perfect sphere, so that minute runs from about 1843 m at the equator to about 1862 m near the poles; in 1929 a conference in Monaco settled on a round 1852 m as the international standard.
A cable is one tenth of a nautical mile: 185.2 m. Watch out for the older definitions, though. The US Navy counted a cable as 120 fathoms (219.5 m) and the Royal Navy as 608 feet (185.3 m). This converter uses the international cable, 0.1 NM.
Frequent questions
How many kilometres is a nautical mile?
Exactly 1.852 km, that is 1852 metres. Ten nautical miles are 18.52 km.
How many cables are in a nautical mile?
Ten. A cable is 0.1 nautical mile, that is 185.2 m; distances of a few cables are what you hear when ships manoeuvre and pass each other.
What is the difference between a nautical and a statute mile?
A statute mile is 1609.344 m, a nautical mile 1852 m. The nautical one is about 15% longer, because it comes from a minute of arc of a meridian rather than from a Roman thousand paces.
Is it written NM, nm or nmi?
You will meet all three. NM is the usual abbreviation in English charts and publications, nmi is the standardised form, and nm strictly means nanometre. It is always the same unit: 1852 m.