Convert Parsec to Sun's Radius
Convert parsecs to sun's radii instantly. 1 parsec = 4.435357e+7 sun's radius — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Sun's Radius to Parsec converter for the reverse conversion.
Units explained
Parsec
A parsec (parallax-second) is a distance unit equal to 648,000/π astronomical units — approximately 3.086×10¹⁶ m (3.26 light years). It is the standard distance unit in professional astronomy.
Defined as the distance at which one astronomical unit subtends an angle of one arcsecond. IAU Resolution B2 in 2015 made this an exact definition: 1 pc = (648,000/π) AU.
Parsecs are used in professional astronomy for stellar distances (Proxima Centauri ≈ 1.3 pc), galactic-scale distances (with prefixes kiloparsec and megaparsec), and parallax measurements. Standard since the early 20th century.
Concept introduced by Herbert Hall Turner in 1913; exact definition via the AU adopted by IAU Resolution B2 in 2015.
Sun's Radius
The Sun's radius is approximately 695,700 km (6.957×10⁸ m), defined as the IAU 2015 nominal solar radius for use in stellar physics and exoplanet research.
The IAU (International Astronomical Union) Resolution B3 in 2015 defined a nominal solar radius of exactly 6.957×10⁸ m to serve as a stable reference, independent of actual measurement-uncertainty variations in the real Sun.
Solar radii are used in stellar physics, exoplanet characterisation, and any context where a star's size is expressed relative to the Sun. Most stellar radius measurements are quoted in solar-radius units rather than meters.
Defined exactly at 6.957×10⁸ m by IAU Resolution B3 in 2015.
Parsec to Sun's Radius conversion formula
The relationship between parsecs and sun's radii:
To convert parsecs to sun's radii, multiply the value in parsecs by 4.435357e+7. To reverse, multiply sun's radii by 2.25461e-8.
How to use this converter
Type a value into the calculator. The result in sun's radii updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Sun's Radius to Parsec converter for the reverse direction.
Step-by-step: convert parsecs to sun's radii
- Write down the value in parsecs (pc).
- Multiply that value by the factor 4.435357e+7.
- The product is the equivalent value in sun's radii (R☉).
- To reverse, multiply the sun's radius value by 2.25461e-8.
Worked examples
Example 1 — Convert 1 pc to R☉:
1 × 4.435357e+7 = 4.435357e+7 R☉
Example 2 — Convert 100 pc to R☉:
100 × 4.435357e+7 = 4.435357e+9 R☉
Parsec to Sun's Radius conversion table
Standard reference values for converting parsecs to sun's radii:
| Parsec [pc] | Sun's Radius [R☉] |
|---|---|
| 0.01 | 443535.6592628098 |
| 0.1 | 4435356.5926280981 |
| 1 | 4.435357e+7 |
| 2 | 8.870713e+7 |
| 3 | 1.330607e+8 |
| 4 | 1.774143e+8 |
| 5 | 2.217678e+8 |
| 10 | 4.435357e+8 |
| 20 | 8.870713e+8 |
| 30 | 1.330607e+9 |
| 40 | 1.774143e+9 |
| 50 | 2.217678e+9 |
| 100 | 4.435357e+9 |
| 500 | 2.217678e+10 |
| 1000 | 4.435357e+10 |
Frequently asked questions
How many sun's radii is 1 parsec?
How do I convert parsecs to sun's radii?
How do I convert sun's radii back to parsecs?
How many sun's radii is 100 parsecs?
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Sources & references
Conversion factor (1 pc = 4.435357e+7 R☉) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.