Length conversion: unit selection

The conversion calculator converts to and from astronomical units, centimeters, decimeters, feet, inches, kilometers, light-years, meters, micrometers, miles, millimeters, nanometers, nautical miles, yards as well as other less commonly used units (see below). Select what you want to convert from and what you want to convert to. Then press the "Conversion calculator" button.

Length conversion calculator


Length is the measurement of distance between two points. It is one of the three fundamental physical quantities: length, mass, time.
Units of length supported by the converter:

astronomical unitauAstronomical units are used to measure the huge distances in space. One astronomical unit is approximately 149 597 870 691 meters.
attometeramMetric system. One Quintillionth of a meter
cablecableCable is a unit of length that was used at sea. One cable is about 219 meters.
centimetercmcentimeter is a unit of length used by the metric system, that is equivalent to 1/100 th of a meter.
chainchOne chain is 100 links
decameterdamThe decameter is a unit of length of the metric system equivalent to 10 m. It's not commonly used.
decimeterdmMetric system. One tenth of a meter
fathomfathomThe fathom represents the distance between a man's outstretched fingertips. It's used mainly at sea.
femtometerfmMetric system. One quadrillionth of a meter
footftThe international foot is equal to 12 inches.
foot (survey)ftThe United States survey foot is defined as 1200/3937 meters.
furlongfurThe furlong is a measure of distance in the imperial system. It's equal to 660 feet.
handhhHand is a unit of length used to measure the height of horses. One hand is 4 inches.
hectometerhmMetric system. 100 meters.
inchinThe international inch, equivalent to 25.40 mm.
kilometerkmA kilometer is another unit of length of the metric system. It's equivalent to 1000 meters.
league (land)leaguesThe league was intended to represent the distance a person can walk in an hour. It's no longer used but is often found in literature (eg.20000 Leagues under the sea).
league (sea)leaguesThe league was intended to represent the discance a person can walk in an hour. It's no longer used but is often found in leterature (eg.20000 Leagues under the sea).
li (Chinese)liA unit of length used in China. One li is 500 m.
light-yearlyThe light-year is the distance light travels in vacuum in one year. It's equivalent to approximately 9,460,730,472,580.8 km.
linkliLink is a unit of length in the Imperial system. It is equal to 33/50 of a foot. It is rarely used.
metermMeter is the basic unit of length in the metric system. The official definition of meter, since 1983 is: the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.
micrometermMetric system. One millionth of a meter
micronEquivalent to micrometer
milmilMil is used in the US in engineering, to specify tolerances. It's equal to 0.001 inch.
milemiOne international mile is 5280 feet.
mile (survey)miOne U.S. survey mile is equal to 8000 links
millimetermmMetric system. One thousandths of a meter
nanometernmMetric system. One billionth of a meter
nautical milenmiNautical mile is a unit of length to specify distance for maritime and aviation purposes. One nautical mile is 1852 meters.
picometerpmMetric system. One trillionth of a meter
rodrdOne rod is 25 links
thouthouOne thou is the same as 1 mil. and is equal to one thousandths of an inch.
yardydThe yard is equivalent to 3 feet.

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