Birthday Paradox Calculator

Created by Davide Borchia
Last updated: Jun 05, 2022
The chance of two people in a group sharing the same birth date rises surprisingly fast as the size of the group increases. Of course, the chance is zero if there is only one person and 100% if there are 366 people. This calculation does not take leap years into account but these have a very small effect.
Davide Borchia
Number of people
Probability
%
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