Convert length and distance units — meters, feet, inches, kilometers, miles, light years and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 au | 4.8477e-09 pc | |
| 0.01 au | 4.8477e-08 pc | |
| 0.1 au | 4.8477e-07 pc | |
| 1 au | 4.8477e-06 pc | |
| 5 au | 2.42385e-05 pc | |
| 10 au | 4.8477e-05 pc | |
| 50 au | 0.000242385 pc | |
| 100 au | 0.00048477 pc | |
| 1000 au | 0.0048477 pc |
Multiply the number of Astronomical Units by 4.8477e-06 to get Parsecs. Formula: pc = au × 4.8477e-06. Example: 10 au × 4.8477e-06 = 4.8477e-05 pc. To reverse, divide Parsecs by 4.8477e-06 to get Astronomical Units.
| Astronomical Unit (au) | Parsec (pc) |
|---|---|
| 0.001 au | 4.8477×10-9 pc |
| 0.01 au | 4.8477×10-8 pc |
| 0.1 au | 4.8477e-07 pc |
| 0.5 au | 2.42385e-06 pc |
| 1 au | 4.8477e-06 pc |
| 2 au | 9.6954e-06 pc |
| 5 au | 2.42385e-05 pc |
| 10 au | 4.8477e-05 pc |
| 20 au | 9.6954e-05 pc |
| 50 au | 0.000242385 pc |
| 100 au | 0.00048477 pc |
| 250 au | 0.00121192 pc |
| 500 au | 0.00242385 pc |
| 1000 au | 0.0048477 pc |
| 10000 au | 0.048477 pc |
To convert Astronomical Unit to Parsec, multiply by 4.8477e-06. Example: 10 au = 4.8477e-05 pc
To convert Parsec back to Astronomical Unit, divide by 4.8477e-06 (multiply by 206283). Use the swap button above.
Start with 100 Astronomical Units = 0.00048477 pc as your reference point. Scale up or down from there.
The parsec is defined by stellar parallax — 1 parsec is the distance at which 1 AU subtends 1 arcsecond. Converting AU to parsecs is therefore built into the fundamental definition of how astronomers measure stellar distances.
Galactic structure is described in kiloparsecs (Milky Way: ~30 kpc diameter), while individual planetary systems within the galaxy are described in AU — astronomers routinely convert between these nested scales.
The Gaia space telescope measures stellar distances in parsecs from parallax observations. Researchers converting these results to AU for comparison with solar system scales need this conversion constantly.
Astrometrists measuring stellar proper motions and parallaxes work in parsecs for distance and arcseconds for angle, but express physical transverse velocities in AU/year — requiring conversion between the two distance units.
Cepheid and RR Lyrae variable star distances — used as cosmic distance ladder rungs — are measured in kiloparsecs, then converted to AU for comparison with local reference standards and calibration objects.
Exoplanet orbital parameters are expressed in AU, while the distance to the host star system is in parsecs. Both appear in every exoplanet discovery paper, requiring readers to fluidly convert between them.
The Astronomical Unit is a unit of Length measurement (symbol: au). 1 au = 4.8477e-06 pc. Used in scientific and practical Length measurement applications.
The Parsec is a unit of Length measurement (symbol: pc). It is part of an internationally recognised measurement system used alongside the Astronomical Unit.
The astronomical unit has ancient roots — Aristarchus of Samos attempted to measure the Earth-Sun distance around 270 BC, estimating it at 18–20 lunar distances (the true value is about 390). For centuries the AU was estimated using Venus transit observations and trigonometry. Edmond Halley organised the first coordinated international transit-of-Venus expedition in 1716. The modern value was determined by radar ranging to Venus in 1961. The IAU formally defined the AU as exactly 149,597,870,700 metres in 2012 — a fixed constant of physics, not a measured distance.
The parsec was introduced in 1913 by British astronomer Herbert Hall Turner as a practical unit for stellar parallax measurements. It equals the distance at which 1 astronomical unit subtends 1 arcsecond — approximately 3.086×10¹³ kilometres or 3.26 light-years. The name blends 'parallax' and 'arcsecond'. Professional astronomers strongly prefer parsecs over light-years because parallax directly yields distance in parsecs without any intermediate calculation.
Common use: Astronomical Unit to Parsec conversion is needed when working with international standards, scientific publications, or reference materials that use different unit systems for Length measurement.