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:
| Unit | Symbol | Description |
|---|---|---|
| astronomical unit | au | Astronomical units are used to measure the huge distances in space. One astronomical unit is approximately 149 597 870 691 meters. |
| attometer | am | Metric system. One Quintillionth of a meter |
| cable | cable | Cable is a unit of length that was used at sea. One cable is about 219 meters. |
| centimeter | cm | centimeter is a unit of length used by the metric system, that is equivalent to 1/100 th of a meter. |
| chain | ch | One chain is 100 links |
| decameter | dam | The decameter is a unit of length of the metric system equivalent to 10 m. It's not commonly used. |
| decimeter | dm | Metric system. One tenth of a meter |
| fathom | fathom | The fathom represents the distance between a man's outstretched fingertips. It's used mainly at sea. |
| femtometer | fm | Metric system. One quadrillionth of a meter |
| foot | ft | The international foot is equal to 12 inches. |
| foot (survey) | ft | The United States survey foot is defined as 1200/3937 meters. |
| furlong | fur | The furlong is a measure of distance in the imperial system. It's equal to 660 feet. |
| hand | hh | Hand is a unit of length used to measure the height of horses. One hand is 4 inches. |
| hectometer | hm | Metric system. 100 meters. |
| inch | in | The international inch, equivalent to 25.40 mm. |
| kilometer | km | A kilometer is another unit of length of the metric system. It's equivalent to 1000 meters. |
| league (land) | leagues | The 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) | leagues | The 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) | li | A unit of length used in China. One li is 500 m. |
| light-year | ly | The light-year is the distance light travels in vacuum in one year. It's equivalent to approximately 9,460,730,472,580.8 km. |
| link | li | Link is a unit of length in the Imperial system. It is equal to 33/50 of a foot. It is rarely used. |
| meter | m | Meter 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. |
| micrometer | µm | Metric system. One millionth of a meter |
| micron | µ | Equivalent to micrometer |
| mil | mil | Mil is used in the US in engineering, to specify tolerances. It's equal to 0.001 inch. |
| mile | mi | One international mile is 5280 feet. |
| mile (survey) | mi | One U.S. survey mile is equal to 8000 links |
| millimeter | mm | Metric system. One thousandths of a meter |
| nanometer | nm | Metric system. One billionth of a meter |
| nautical mile | nmi | Nautical mile is a unit of length to specify distance for maritime and aviation purposes. One nautical mile is 1852 meters. |
| picometer | pm | Metric system. One trillionth of a meter |
| rod | rd | One rod is 25 links |
| thou | thou | One thou is the same as 1 mil. and is equal to one thousandths of an inch. |
| yard | yd | The yard is equivalent to 3 feet. |
Recently updated conversion pages
The following pages have recently been updated with conversion formulas and more information:
- From centimeters:
- From micrometers:
- From microns:
- From mils:
- From millimeters:
- From thou: