Convert Nautical Miles to Kilometers

About converting Nautical Miles to Kilometers

Nautical Miles (nmi) and Kilometers (km) are both units of length, so converting between them is a single multiplication: multiply your Nautical Miles figure by 1.852. Ten Nautical Miles comes to 18.52 Kilometers, and a hundred works out at 185.2 Kilometers.

Rule of thumb: going from Nautical Miles to Kilometers multiplies, so the figure always grows — one Nautical Mile is already 1.852 Kilometers. If your answer came out smaller, you have the conversion the wrong way round.

What is a Nautical Mile?

A nautical mile is exactly 1,852 meters, and unlike every other unit here it was chosen to mean something geographically: it is one minute of latitude, one sixtieth of a degree. That is enormously convenient at sea and in the air, because a navigator can read distance straight off a chart’s latitude scale with dividers and no arithmetic. It is also the parent of the knot — one nautical mile per hour — which is why ships and aircraft report speed in knots rather than km/h.

What is a Kilometer?

A kilometer is exactly 1,000 meters — the "kilo" prefix means a thousand, as it does everywhere in the metric system. It is the unit almost every country uses for road distances and speed limits, the main exceptions being the United States and the United Kingdom, which still post miles. Its convenience is that it sits at a human scale for travel: a brisk walk covers roughly a kilometer in ten to twelve minutes, which is why city planners talk about the "fifteen-minute" neighbourhood in these terms.

To put both in perspective: a nautical mile is one minute of latitude on any chart, while a kilometer is about a twelve-minute walk.

The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Kilometers to Nautical Miles converter, or browse all Length converters.