Birthday Paradox Probability
Estimate the probability that at least two people in a group share the same birthday.
CalcSimpler Examples
- Group of 23 ⇒ 50.73%
- Group of 50 ⇒ 97.04%
FAQ
What assumptions are made?
All 365 days are equally likely and birthdays are independent.
Are leap years considered?
No, February 29 is ignored.
Is the result a percentage?
Yes, values range from 0 to 100%.
When does probability exceed 99%?
Around 57 people.
Additional Information
- Probability is 1 minus the chance that all birthdays are different.
- Assumes a 365-day year with each date equally likely and independent.
- Real-world birth rates are not perfectly uniform, so actual odds vary slightly.
CalcSimpler