How do I convert from Kilometers to UK nautical miles?
Divide by 1.853184. A UK nautical mile is 6,080 ft, which works out at exactly 1,853.184 m, so 100 km comes to 53.96 UK nautical miles.
Multiplying by 0.54 is a decent shortcut – 100 km gives 54, under 0.1% high and closer than most charts are drawn.
For the international nautical mile divide by 1.852 instead; the two answers differ by less than a tenth of a percent.
What is a kilometer?
A kilometer is 1,000 meters, or about 0.621 miles. 'Kilo' is the Greek-derived prefix for a thousand. It is the unit for road distances nearly everywhere except the US and UK, which still use miles.
A kilometer is about 3,281 feet or 39,370 inches. At a walking pace of 5km/h it takes about 12 minutes to cover.
Going from kilometers to meters just means moving the decimal point three places. A mile has to be broken into 1,760 yards or 5,280 feet first, and neither of those is a round number of anything.
What is a UK Nautical Mile?
The UK nautical mile was based on one minute of latitude, ie 1/60th of a degree. The Earth is not a perfect sphere, so a minute of latitude varies slightly with latitude, which is why a fixed length had to be chosen.
The UK nautical mile, also called the Admiralty mile, was fixed at 6,080 feet, which is 1,853.184 meters. That is 1.184 meters longer than the international nautical mile of 1,852 meters (6,076.11549 feet), which the UK adopted in 1970.