Birthday Paradox

In-app purchases
100+
Downloads
Content rating
PEGI 3
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About this app

In a classroom, what is the probability that 2 students will celebrate their birthdays on the same day? With 365 days a year, around thirty students in the class, we say to ourselves that it must be weak …

Think again!

It only takes 23 people for there to be more than a 50% chance that 2 people will have their birthday on the same day. From 41 people, the probability is more than 90%!

This is what this simple application will allow you to experiment.

Try with dates of birth, car numbers etc …
Updated on
Aug 20, 2025

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
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No data collected
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What’s new

Android 16