Exact model
A shared birthday in a room of 50
- Probability:
- 97.04%
- Odds:
- 33 to 1
- dBan
- +15.2 dBan
Gather 50 people and only about three modelled groups in 100 avoid a shared birthday.
Calculation
p = 1 − ∏ₖ₌₀⁴⁹ (365 − k) / 365 ≈ 0.97037358
Assumptions
Birthdays are independent and equally spread over 365 dates. Leap days are ignored.
Sources
- Uniform 365-day birthday model