Astronomical Distance Converter
Convert astronomical units, light-years, parsecs, kilometres and solar radii.
Results
Result
0.306601
pc
1 ly equals 0.306601 pc
What this tool does
Three of these units are now exact by definition rather than by measurement: the astronomical unit was fixed at 149 597 870 700 metres in 2012, the light-year follows from the Julian year and the defined speed of light, and the parsec is 648 000/π astronomical units. That means the conversions here carry no measurement uncertainty at all, which surprises people who assume astronomy is always approximate. A parsec is about 3.26 light-years, and the nearest star is a little over one parsec away.
Worked example
1 ly 0.306601 pc
Conversion table
| Unit | Result |
|---|---|
| Metre m | 9.46073e+15 |
| Kilometre km | 9,460,730,472,580 |
| Mile mi | 5,878,625,373,180 |
| Light-second ls | 31,557,600 |
| Light-minute lmin | 525,960 |
| Astronomical unit au | 63,241.1 |
| Parsec pc | 0.306601 |
| Kiloparsec kpc | 0.000306601 |
| Megaparsec Mpc | 0.0000003066 |
| Solar radius (nominal) R☉ | 13,598,865 |
| Earth radius (nominal equatorial) R⊕ | 1,483,314,854 |
Convert a whole list
One value per line. The units above are used for every line.
Limitations
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.