Astronomy
Light years and parsecs
Converts between the two units astronomers use for stellar distances. Divide light years by 3.26156 to get parsecs.
The Formula
1 parsec = 3.26156 light years
Converts between the two units astronomers use for stellar distances. Divide light years by 3.26156 to get parsecs.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| ly | Distance in light years | light years | The light travel distance. |
| pc | Distance in parsecs | parsecs | The parallax-based distance. |
What Each Symbol Means
lylight years
Distance in light years
The light travel distance.
pcparsecs
Distance in parsecs
The parallax-based distance.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate light years page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Light Years, filed under Science. Every number the guide produces comes from substituting into this one line.