© Semhur (commons.wikimedia.org) A Kilometre and Mile Unit Comparison Scale
© Semhur (commons.wikimedia.org)
Basics of kilometres and miles
The kilometre (symbolised as km) is a distance unit in the metric system mostly used to express geographical distances. It is equal to 1,000 metres which is the base unit of length in the International System of Units (SI).
Other multiple units of the metric system are centimetres (cm), where 100 cm equals 1 metre, and the millimetres (mm) where 1000mm equals 1m. France was the first to adopt the metric system in 1799 and since then, its use has become international.
The most notable exceptions are the United Kingdom and the United States who both still use a different unit of measurement when referring to geographical distances, the mile.
The mile (symbolised as mi, ml, m, or M) is a unit of length that was firstly defined in 1592 by the English Act of Parliament, and it commonly refers to the statute or land mile; the exact conversions rates.
The nautical mile (or M, NM or nmi) equals to the length of a minute of arc upon the planet Earth. It is longer than the statute mile, however it is widely used by all nations for air and sea distances, since it is convenient when working with charts.
Distance unit conversions
There are many online tools that convert miles to kilometres (mi to km), kilometers to meters (km to m) or miles (km to mi), etc. However, it is only necessary to know the following:
The equivalence of a kilometre to other units of length is the following: 1 km (kilometre) = 1000 m (metres) = 0.621 mi (statute miles) = 0.540 nmi (nautical miles)
Correspondingly, the conversions for 1 mile or 1 nautical mile are: 1 mi = 1.609344 km = 1,760 yd = 5,280 ft 1 nmi = 1.852 km = 2,025.372 yd = 6,076.115 ft
Other types of miles
The data mile is another type of mile used by the Royal Navy for monitoring ballistic, cruise and anti-ship missiles with the aid of radars. It is equal to 0.987 nmi or 1.8288 km. The radar mile is used in radar theory and represents the amount of time that it takes for a pulse to travel a data mile forth and a data mile back. This time is equal to 12,277 μs and is used to determine the radar’s range.
