Calculate the probability of shared birthdays in a group. Surprisingly high!
Calculate the probability of shared birthdays in a group. Surprisingly high!
P = 1 - ∏(365-i)/365
23 people → 50.7% chance of a shared birthday!
Enter values above and click Calculate. All computation happens locally in your browser — no data is sent to any server.
What is Birthday Paradox Calculator?
Calculate the probability of shared birthdays in a group. Surprisingly high!
Formula used?
P = 1 - ∏(365-i)/365
Is it free?
Yes! All CalcNest AI tools are 100% free.
Is my data safe?
All calculations run locally. We never store or transmit your data.