How big are the stars compared with the Sun?
The Sun is an unremarkable star, and the largest known would swallow the orbit of Saturn.
Almost exactly the Sun
1,391,400 km is bigger than 4 of the 10 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| Sirius B | 11,700 km | 119× | A white dwarf, Earth-sized |
| Earth | 12,742 km | 109× | |
| Jupiter | 139,820 km | 9.95× | |
| Proxima Centauri | 214,000 km | 6.5× | |
| the Sun | 1,391,400 km | 1× | |
| Sirius A | 2,380,000 km | 0.585× | |
| Arcturus | 36,000,000 km | 1/25.9 | |
| Rigel | 110,000,000 km | 1/79.1 | |
| Betelgeuse | 1,200,000,000 km | 1/862 | |
| UY Scuti | 2,400,000,000 km | 1/1,725 | Among the largest known |
Worth knowing
- UY Scuti is about 1 700 times the Sun’s diameter. Placed at the centre of the solar system, its surface would reach past Jupiter.
- A white dwarf packs a Sun’s worth of mass into an Earth-sized ball; a teaspoon of it would weigh about a tonne.
Frequently asked
What is the biggest star?
Candidates like UY Scuti and Stephenson 2-18 are quoted at 1 500–2 100 solar radii, but these stars have no sharp edge and the measurements carry large uncertainties.
Is the Sun a big star?
No — it is a G-type main sequence star, larger than about 90% of stars in the galaxy but tiny next to any giant. Most stars are red dwarfs, much smaller than the Sun.