Nautical Miles to Kilometers

A nautical mile is a distance unit used at sea and in aviation, and it is defined from Earth’s geometry rather than an arbitrary length. One nautical mile equals exactly 1.852 kilometers, so converting from nmi to km is just a multiplication by this factor. This works because kilometers are the metric distance unit used on land, while nautical miles are calibrated to latitude and navigation measurements.

Use this formula when converting chart distances,航海/flight route lengths, or any navigation problem given in nautical miles into kilometers. It is also useful when comparing marine or aviation distances with metric road or map distances.

• using 1.85 instead of 1.852 and losing accuracy
• multiplying by the wrong conversion direction when starting from kilometers
• forgetting that the result should be in kilometers, not nautical miles