Estimate
A randomly chosen star is on the main sequence
- Probability:
- 90%
- Odds:
- 9 to 1
- dBan
- +9.5 dBan
About nine in ten stars are main-sequence stars, actively fusing hydrogen in their cores.
Calculation
p ≈ 0.90 by stellar count
Assumptions
This is an approximate fraction by number of stars. It is not a share of stellar mass or of a star’s lifetime, and individual populations can differ.
Sources
- NASA: star types main-sequence share by stellar count checked 27 October 2026