how many stars are there in the universe
There is no exact, counted number of stars in the universe, but current scientific estimates put the total in the observable universe at roughly between 102210^{22}1022 and 102410^{24}1024 stars.
Quick answer
- A commonly quoted rough figure is about 102210^{22}1022 stars (10 sextillion).
- Some methods give higher ranges up to about 4.5×10244.5\times 10^{24}4.5×1024 stars.
- Any specific number is an estimate , not a direct count, and will be refined as observations improve.
How scientists get that number
Astronomers cannot count individual stars; instead they estimate based on galaxies.
- Estimate stars in a typical galaxy
- The Milky Way is thought to have on the order of 100–400 billion stars.
- Estimate how many galaxies there are
- Deep surveys suggest around 200 billion to perhaps 2 trillion galaxies in the observable universe.
- Multiply the two
- Taking 100 billion stars per galaxy and 2 trillion galaxies gives about 2×10232\times 10^{23}2×1023 stars (often rounded to about 200 sextillion).
Different assumptions about “typical” galaxies and how much light they contribute give a range rather than a single value, which is why you see estimates from about 102210^{22}1022 up to a few 102410^{24}1024.
A couple of concrete examples
- One popular educational estimate uses:
- 100 billion stars in a typical galaxy,
- 2 trillion galaxies,
- leading to roughly 200 billion trillion (200 sextillion) stars.
- A research-summary site notes that:
- Combining various observational methods suggests the observable universe likely contains between 102210^{22}1022 and 102410^{24}1024 stars overall.
So when people ask “how many stars are there in the universe?”, the best honest answer is: an unimaginably huge number, on the order of 102210^{22}1022–102410^{24}1024 stars in the observable part of it, and we will never know the exact figure.
Information gathered from public forums or data available on the internet and portrayed here.