Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Probability
Birthday Paradox Calculator
Calculate the probability that at least two people in a group share a birthday. Useful for teaching probability concepts or settling that classic party debate.
Fill in the required fields to see your result.
Probability
Birthday Paradox Calculator
Find the surprisingly high probability that at least two people in a group share a birthday. Use it to demonstrate why coincidences are far more likely than intuition suggests.
Fill in the required fields to see your result.
Key differences
| Birthday Paradox Calculator | Birthday Paradox Calculator | |
|---|---|---|
| Category | Probability | Probability |
| Inputs required | 4 | 2 |
| Result | Result | Probability of Match |
| What it does | Calculate the probability that at least two people in a group share a birthday. Useful for teaching probability concepts or settling that classic party debate. | Find the surprisingly high probability that at least two people in a group share a birthday. Use it to demonstrate why coincidences are far more likely than intuition suggests. |