Unit Converter

Convert between common units of length, mass, temperature, area, volume, speed, pressure, energy, power, time, data, angle and frequency, from millimeters to light-years. Pick a unit, type a value and read the result with as many decimals as you want.

Everything runs locally in your browser. Your data never leaves your device.

1 km is

0.62137mi

Decimals

In every length unit

1 km expressed in the other units it can convert to.

Nanometer

999,999,999,999.9999nm

Micrometer

1,000,000,000µm

Millimeter

1,000,000mm

Centimeter

100,000cm

Meter

1,000m

Inch

39,370.07874in

Foot

3,280.8399ft

Yard

1,093.6133yd

Mile

0.62137mi

Nautical mile

0.53996nmi

Astronomical unit

6.68459e-9au

Light-year

1.05700e-13ly

Parsec

3.24078e-14pc

About the Unit Converter

This tool converts a value from one unit to another. Pick the unit you have, type the value, pick the unit you want and read the result. It covers length, mass, temperature, area, volume, speed, pressure, energy, power, time, data, angle and frequency.

The target list only ever shows units the source can actually convert to, so you cannot ask for kilometers in bar. The result shows 5 decimals by default, and a small input lets you raise or lower that.

What you can do

Convert metric to imperial and back, like km to miles or kg to pounds.
Convert temperatures between Celsius, Fahrenheit and Kelvin.
Convert pressure between bar, psi, atm, pascal and torr.
Convert digital storage between bits, bytes, and decimal or binary multiples.
Convert astronomical lengths like light-years, astronomical units and parsecs.
Choose how many decimals the result shows.
Swap the two units with one click.

How to use the Unit Converter

1Pick the unit you are converting from. Units are grouped by what they measure.
2Type the value.
3Pick the unit you want. Only compatible units are offered.
4Read the result, adjust the decimals if you need more or fewer, and copy it.

Notes on specific units

Data units come in both flavours: decimal ones like kilobyte and megabyte are powers of 1000, and binary ones like kibibyte and mebibyte are powers of 1024. A month is treated as the average Gregorian month and a year as 365.25 days. Fluid ounces, cups, pints, quarts and gallons are the US measures, with the imperial gallon listed separately.

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