# Astronomical unit conversions

length conversions » astronomical unit conversionsThe online converter calculator on this page allows you to select the length/distance measurement unit you want to convert to starting from astronomical units (AU). To make a conversion starting from a unit of length other than astronomical unit, simply click on the "Reset" button.

## What is astronomical unit?

### Definition:

The astronomical unit is a unit of distance used in astronomy equal to approximately 149,597,870.7x103 meters (1 AU ≈ 149.60x109 m), the base unit of length in the International System of Units (SI). It is also equal to approximately 149.60x106 kilometers (km) (an SI unit of length), or 92.956x106 miles (mi), or 490.81x109 feet (ft) or 1.636x1011 yards (yd), which are US customary / Imperial units of length.

The astronomical unit is an approximate astronomical measurement unit of distance as it depends on the heliocentric gravitational constant which is the product of the gravitational constant G and the solar mass. Neither the gravitational constant nor the solar mass can be measured to high accuracy in SI units. Common astronomical measurement units include the parsec (1 AU ≈ 4.8481x10-6 pc) and the light-year (1 AU ≈ 15.813x10-6 ly).

### Symbol:

AU

### Plural:

astronomical units

Below you can find a comprehensive list with conversions from astronomical units to other (metric, imperial, or customary) length and distance measurement units.