Astronomical unit to Light-year
Convert Astronomical unit to Light-year instantly. Free online astronomy unit converter with exact formula, conversion table and FAQ.
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Astronomy Converter
Convert astronomical length, mass, time, and distance units by compatible family.
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Formula
light-year = astronomical unit × 1.58125074e-5
astronomical unit = light-year × 63241.07708
Conversion table
| 1 AU | 1.58125074e-5 ly |
| 5 AU | 7.9062537e-5 ly |
| 10 AU | 0.0001581250741 ly |
| 20 AU | 0.0003162501482 ly |
| 50 AU | 0.0007906253705 ly |
| 100 AU | 0.001581250741 ly |
| 500 AU | 0.007906253705 ly |
| 1,000 AU | 0.01581250741 ly |
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Frequently asked questions
What is the source unit in this conversion?
The source unit is the astronomical unit (AU). An astronomical unit (AU) is the mean Earth-Sun distance, about 149.6 million kilometers.
What is the destination unit in this conversion?
The destination unit is the light-year (ly). A light-year is the distance light travels in one Julian year through a vacuum.
How do I convert astronomical unit to light-year?
Multiply the astronomical unit value by 1.58125074e-5. For example, 10 AU × 1.58125074e-5 = 0.0001581250741 ly.
Is the astronomical unit to light-year conversion exact?
Yes. Both units have a fixed, defined relationship to the astronomy converter's distance base unit, so the conversion factor is exact rather than a measured approximation.
Where is this conversion commonly used?
It's used in astronomy, physics, and space science whenever a distance value expressed in astronomical unit needs to be compared with, or reported in, light-year.
Can I convert light-year back to astronomical unit?
Yes. Multiply the light-year value by 63241.07708 to get astronomical unit.
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About this conversion
This page converts astronomical unit (AU) to light-year (ly) within the astronomy converter.
An astronomical unit (AU) is the mean Earth-Sun distance, about 149.6 million kilometers.
A light-year is the distance light travels in one Julian year through a vacuum.
The formula is light-year = astronomical unit × 1.58125074e-5, based on each unit's fixed relationship to the astronomy converter's distance base unit.
The conversion is exact, since it relies on a fixed numerical ratio between the two units rather than a measured or approximate value.
Use the calculator above for instant results, or the table below for common astronomical unit values already converted to light-year.