Length Conversion Calculator

Converts Metric, British, Chinese, and Japanese length units

Convert length units

This calculator converts a specified length in Metric, Imperial, Nautical, Astronomical, Chinese and Japanese units of measure.

Select the unit of measurement that you know and enter its value. Then click on 'Calculate'.

The number of decimal places or the Floating point representation can be set.

Calculate lengths

 Enter the unit of measurement and the length
Decimal places
nanometer   nm
micrometer   µm
millimeter   mm
centimeter   cm
meter   m
kilometer   km
inch   in
feet   ft
yard   yd
mile   mi
nautical mile   nmi
astronom. unit   AU
light-year   ly
parsec   pc
市里 li   市里
yin   引
市丈 zhang   市丈
bu   步
市尺 chi   市尺
市寸 cun   市寸
市分 fen   市分
市厘 li   市厘
hao   毫
si   丝
hu   忽
sun   寸
shaku   尺
鯨尺 kuzirazyaku   鯨尺
jo   丈
ken   間
cho   町
ri   里

Common units of measure

At the international level, the metric system was established with the meter as the basis for length in the international system of units SI (Système international d'unités) to standardize the units of measurement. Nevertheless, other units are also used. The units of length mile, yard, foot and inch are mainly used in the Anglo-American. In astronomy, units such as light year, astronomical unit or parsec are used for calculations. The nautical units of measurement, nautical miles, are used in aviation and shipping.


The metric system with the meter as the base unit is the system of units for the length of a distance. In contrast to other systems, you can easily calculate with decimal multiples or fractions.

Anglo-American (Imperial) units of length

The imperial units of length do not belong to the international system of units, so they are not SI-compliant. The mile is used, the length of which is 1.609344 kilometers. 1 yard is 3 feet and is 0.9144 meters in length. 1 foot is 30.48 centimeters which is the equivalent of 12 inches. 1 inch in turn corresponds to 2.54 cm.

Nautical units of length

The nautical mile is a general one in shipping and aviation Unit of measure used for length. It was precisely defined at 1,852.0 m.

Astronomical units of length

These units of length are used in astronomy to describe the enormous proportions. They do not belong to the international system of units, but are indispensable for the description of distances in astronnomy.

A light year is the distance that light travels in a year. The Julian year (365.25 days) was set as the basis for the definition of the light year. One light year is 9,460,730,472,580.8 km. The parsec corresponds to around 3.26 light years. The astronomical unit (AU) corresponds to the mean distance between the earth and the sun. By definition, it has a length of 149,597,870,700 meters.

Chinese units of length

The Ancient Traditional Weights and Measures of China is parallel to the International system of units still in use in modern China. The standard of the system of units from the imperial time of China becomes Shìzhì called and was named at the beginning of the 20th century depending on the appropriate SI units redefined and used.

Japanese units of length

Although trade has been limited to the use of the metric system since the beginning of the 20th century, Old Japanese units of measurement are still used in some cases. The old measures are often found in carpentry and agriculture. The floor area is given in tatami mats and land is sold according to the price in tsubo.

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