There are different types of Leagues
There are a few different types of League. On this site we have conversions for US Leagues and UK Leagues. In addition, there are also Nautical Leagues which can be found on this site. Please either select the appropriate unit on the selection above of click the required unit in the links below:
What is a US Nautical Mile?
A US nautical mile is a unit of measurement used primarily in navigation and marine activities. It is defined as exactly 1,852 meters or approximately 6,076.12 feet. The term "nautical mile" originated from the need for sailors to measure distances on the Earth's surface while taking into account the curvature of the Earth.
The US nautical mile is based on the international nautical mile, which was agreed at the First International Extraordinary Hydrographic Conference in Monaco in 1929. The length was set at 1,852 meters, close to one minute of latitude. The Earth is not a perfect sphere, so a minute of latitude varies slightly with latitude, but for practical purposes the US nautical mile is a fixed value.
Speed over water is measured in knots, one knot being one nautical mile per hour, so 10 knots is 18.52km/h. The US only adopted the 1,852 meter nautical mile in 1954 – it previously used a slightly longer one.
What is a League?
A league was originally roughly the distance a person could walk in an hour, about 3 miles (4.8 kilometers). The exact length varied with the country and the period.
A league is an old unit of length, usually around 3 miles or 5 kilometers, though the exact figure varied by country and period. Jules Verne's Twenty Thousand Leagues Under the Sea is about distance travelled, not depth – 20,000 of his 4 kilometer leagues is 80,000 kilometers, twice around the Earth.