Sun's Radius to Astronomical Unit Converter
Unit Converter
Instant · Precise · Universal
32 units available
6 categories total
How to Convert Sun's Radius to Astronomical Unit
To convert solar radii to km: multiply by 696,340. To convert solar radii to AU: multiply by 0.00465.
1 R☉ = 6.9634 × 10⁸ m = 696,340 km ≈ 109 × Earth's radius ≈ 0.00465 AU.
For example, 1 Sun's Radius (R☉) = 0.004654745397 Astronomical Unit (AU).
Sun's Radius to Astronomical Unit — Common Values
| Sun's Radius (R☉) | Astronomical Unit (AU) |
|---|---|
| 0.1 | 0.0004654745397 |
| 0.5 | 0.002327372698 |
| 1 | 0.004654745397 |
| 2 | 0.009309490793 |
| 5 | 0.02327372698 |
| 10 | 0.04654745397 |
| 25 | 0.1163686349 |
| 50 | 0.2327372698 |
| 100 | 0.4654745397 |
| 500 | 2.327372698 |
| 1000 | 4.654745397 |
About Sun's Radius (R☉)
Definition
The solar radius is the radius of the Sun, approximately 6.9634 × 10⁸ meters (about 696,340 km).
Mathematical Relationship
1 R☉ = 6.9634 × 10⁸ m = 696,340 km ≈ 109 × Earth's radius ≈ 0.00465 AU.
Conversion Formula
To convert solar radii to km: multiply by 696,340. To convert solar radii to AU: multiply by 0.00465.
Practical Applications
Describing stellar sizes: Betelgeuse ≈ 700 R☉, Sirius ≈ 1.7 R☉, a white dwarf ≈ 0.01 R☉.
Interesting Facts
You could line up about 109 Earths across the Sun's diameter. The largest known star (UY Scuti) is about 1,700 R☉.
Common Mistakes
Confusing solar radius with solar diameter — the diameter is 2 R☉. Also, stellar catalogs list radius, not diameter.
Educational Tips
The Sun's radius (109 × Earth) gives a sense of scale: you could fit over a million Earths inside the Sun by volume.
About Astronomical Unit (AU)
Definition
The astronomical unit is a unit of length approximating the mean Earth-Sun distance, defined as exactly 149,597,870,700 meters.
Mathematical Relationship
1 AU = 149,597,870,700 m ≈ 149.598 Gm ≈ 499 light-seconds ≈ 8.317 light-minutes.
Conversion Formula
To convert AU to km: multiply by 149,597,870.7. To convert AU to light-years: divide by 63,241.
Practical Applications
Spacecraft mission planning, expressing planetary orbit sizes, and solar system scale models.
Interesting Facts
Light takes about 8 minutes and 20 seconds to travel 1 AU. Mars is about 1.52 AU from the Sun, Jupiter about 5.2 AU.
Common Mistakes
Thinking the AU is the exact Earth-Sun distance — Earth's actual distance varies from ~147 to ~152 Gm over the year due to orbital eccentricity.
Educational Tips
AU makes the solar system manageable: Mercury ≈ 0.39 AU, Venus ≈ 0.72, Earth = 1, Mars ≈ 1.52, Jupiter ≈ 5.2, Saturn ≈ 9.5.