# Parsecs to Light years Converter

Use this converter to easily convert between Parsecs and Light years (pc to ly).

*Quick navigation:*

- How many Light years equal one Parsec?
- Difference between Parsecs and Light years
- How to convert Parsecs to Light years?
- pc to ly conversion table

* * How many Light years equal one Parsec?

Approximately 3.26 light years equal one parsec. With accuracy to six decimal places, one parsec is equal to 3.261563 light years. The international symbol for light years is "ly" whereas for parsec it is "pc" so using this notation 1pc = 3.26ly.

* * Difference between Parsecs and Light years

Parsecs were historically used because distances between astronomical bodies were measured using the trigonometric parallax method. The parsec is defined as the distance at which a star will show an annual parallax of one arcsecond, meaning it is based on two arbitrary quantities, characteristic of an Earth-based observer. One is the radius of our planet's orbit and the other is the choice to divide a circle in 360 degrees. This makes it ill-suited as a universally applicable unit.

On the other hand, light years express the distance covered by light in one year's time and while a year is an Earth-based time slice, it does not depend on other quantities except for the speed of light which is a universal constant. It can be argued that the light year is therefore a more suitable unit for distances on the astronomical scale.

* * How to convert Parsecs to Light years?

Knowing that 1 parsec equals 3.26 light-years, to convert from pc to ly one needs to divide the measurement in parsecs by 3.26 in order to get the light-years equivalent. See the example below for a detailed calculation. Of course, using our pc to ly converter above is much easier.

#### Light years to parsecs conversion example

Sample task: * convert 2 parsecs to light years*. Solution:

*Formula:*

pc * 3.261563 = ly

*Calculation:*

2 pc * 3.2616 = 6.523126 ly

*End result:*

2 pc is equal to 6.523126 ly

* * pc to ly conversion table

pc | ly |
---|---|

1 pc | 3.261563 ly |

2 pc | 6.523126 ly |

3 pc | 9.784689 ly |

4 pc | 13.046252 ly |

5 pc | 16.307815 ly |

6 pc | 19.569378 ly |

7 pc | 22.830941 ly |

8 pc | 26.092504 ly |

9 pc | 29.354067 ly |

10 pc | 32.615630 ly |

20 pc | 65.231260 ly |

30 pc | 97.846890 ly |

40 pc | 130.462520 ly |

50 pc | 163.078150 ly |

60 pc | 195.693780 ly |

70 pc | 228.309410 ly |

80 pc | 260.925040 ly |

90 pc | 293.540670 ly |

100 pc | 326.156300 ly |

200 pc | 652.312600 ly |

300 pc | 978.468900 ly |

400 pc | 1,304.625200 ly |

500 pc | 1,630.781500 ly |

600 pc | 1,956.937800 ly |

700 pc | 2,283.094100 ly |

800 pc | 2,609.250400 ly |

900 pc | 2,935.406700 ly |

1,000 pc | 3,261.563000 ly |

* * References

1 NIST Special Publication 330 (2008) - "The International System of Units (SI)", edited by Barry N.Taylor and Ambler Thompson

2 International Organization for Standardization (1993). ISO Standards Handbook: Quantities and units (3rd edition). Geneva: ISO. ISBN 92-67-10185-4.

#### Cite this converter & page

If you'd like to cite this online converter resource and information as provided on the page, you can use the following citation:

Georgiev G.Z., *"Parsec to Light Years Converter"*, [online] Available at: https://www.gigacalculator.com/converters/convert-parsec-to-light-year.php URL [Accessed Date: 06 Jun, 2023].