# Astronomical Units to Parsecs (au to pc)

Source: https://www.unitconvertercalculator.com/length/astronomical-units-to-parsecs/

**1 au = 4.8481368110954E-6 pc**

One astronomical unit equals approximately 4.848 x 10-6 parsecs, or about 4.85 millionths of a parsec. This conversion is fundamental in professional astronomy, linking the solar system distance unit (AU) with the interstellar distance unit (parsec). It derives directly from the geometric definition of the parsec.

## Formula

Convert Astronomical Units to Parsecs

## Conversion Table

| Astronomical Units (au) | Parsecs (pc) |
|---|---|
| 0.1 au | 4.8481368110953E-7 pc |
| 0.39 au | 1.8907733563272E-6 pc |
| 0.72 au | 3.4906585039886E-6 pc |
| 1 au | 4.8481368110954E-6 pc |
| 1.52 au | 7.3691679528649E-6 pc |
| 5.2 au | 2.5210311417696E-5 pc |
| 9.5 au | 4.6057299705406E-5 pc |
| 19.2 au | 9.3084226773031E-5 pc |
| 30 au | 0.00014544410433286 pc |
| 39.5 au | 0.00019150140403827 pc |
| 100 au | 0.00048481368110954 pc |
| 1000 au | 0.0048481368110954 pc |
| 10000 au | 0.048481368110954 pc |
| 100000 au | 0.48481368110954 pc |
| 206265 au | 1.0000009393406 pc |

## Units

### Astronomical Unit (au)

Exactly 149,597,870,700 meters by IAU 2012 definition. Roughly the average distance from the Earth to the Sun. Used for distances within our solar system.

### Parsec (pc)

The distance at which one astronomical unit subtends an angle of one arcsecond. Approximately 3.26 light-years or 30.857 trillion kilometers. The standard unit in professional astronomy.

## Background

By definition, a parsec is the distance at which 1 AU subtends an angle of 1 arcsecond. This means 1 parsec = 206,265 AU. The nearest star, Proxima Centauri, is about 1.30 parsecs (268,332 AU) away. This AU-to-parsec conversion is one of the most frequently used in professional astrophysics.

## Good to Know

The AU-parsec relationship is where solar system science meets stellar astronomy. It is the bridge between Kepler's laws (which use AU) and stellar parallax measurements (which yield parsecs). Every astrophysicist learns this conversion early in their career.

## FAQ

### How many parsecs is 1 AU?

One AU equals approximately 4.848 x 10-6 parsecs, or 1/206,265 of a parsec. This relationship derives directly from the geometric definition of the parsec.

### How many AU are in 1 parsec?

One parsec contains approximately 206,265 AU. This is an exact geometric relationship: 1 parsec is the distance at which 1 AU subtends 1 arcsecond.

### Why is the AU-parsec relationship important?

The parsec is defined in terms of AU and parallax angle. When astronomers measure a star's parallax in arcseconds, dividing 1 by the parallax gives the distance directly in parsecs. Each parsec equals 206,265 AU. This makes the conversion fundamental to stellar distance measurement.

## Non-Frequently Asked Questions

### Is a parsec bigger than an AU?

Much bigger. 1 parsec = 206,265 AU. A parsec is the distance at which 1 AU subtends 1 arcsecond of angle. Think of it this way: if 1 AU is a step, 1 parsec is a 200-kilometer hike.

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## See Also

- [Parsecs to Astronomical Units](https://www.unitconvertercalculator.com/length/parsecs-to-astronomical-units/)