›› Measurement unit: astronomical unit

Full name: astronomical unit

Plural form: astronomical units

Symbol: AU

Category type: length

Scale factor: 149597870691


›› SI unit: metre

The SI base unit for length is the metre.
1 metre is equal to 6.6845871226706E-12 astronomical unit.


›› Convert astronomical unit to another unit

Convert astronomical unit to  

Valid units must be of the length type.
You can use this form to select from known units:

Convert astronomical unit to  


›› Definition: Astronomical unit

The astronomical unit (AU or au or a.u. or sometimes ua) is a unit of length. It is approximately equal to the mean distance between the Earth and Sun. The currently accepted value of the AU is 149 597 870 691 ± 30 metres (about 150 million kilometres or 93 million miles).

The symbol "ua" is recommended by the Bureau International des Poids et Mesures, but in the United States and other anglophone countries the reverse usage is more common. The International Astronomical Union recommends "au" and international standard ISO 31-1 uses "AU".


›› Sample conversions: astronomical unit

astronomical unit to legua [Spanish, post-1568]
astronomical unit to twain
astronomical unit to kiloyard
astronomical unit to line [small]
astronomical unit to shackle
astronomical unit to microinch
astronomical unit to chain [Gunter, survey]
astronomical unit to chinese foot
astronomical unit to Scots mile
astronomical unit to lap [competition]