There is more than one type of Nautical Mile

There are a few different types of Nautical Mile. On this site we have conversions for US Nautical miles, UK Nautical miles and International Nautical miles. Please either select the appropriate unit on the selection above of click the required unit in the links below:

US Nautical miles

UK Nautical miles

International Nautical miles

What is a micrometer?

A micrometer (µm; micrometre outside the US) is 0.000001 meters. The µ is the Greek letter mu, the SI symbol for the prefix micro.

A micrometer is a millionth of a meter, the scale of things you need a microscope for. A red blood cell is about 7 micrometers across and a human hair about 70.

The unit shares its name with the micrometer screw gauge, the hand tool for measuring small parts. That usually reads to 0.01mm, which is 10 micrometers, so the micrometer mostly doesn't measure in micrometers.

What is a nautical mile?

A nautical mile is the unit of distance at sea and in the air, and is exactly 1,852 meters. It began as one minute of latitude along any meridian, which varies slightly because the Earth is not a perfect sphere, so a fixed length was agreed internationally.

Latitude is the reason for the length: a degree has 60 minutes, so a nautical mile is a sixtieth of a degree and 21,600 of them go round the Earth. That makes the latitude scale on a chart a distance scale too. Territorial waters extend up to 12 nautical miles from a coast.