Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Probability
Statistical Power Calculator
Calculates the statistical power of a hypothesis test or the sample size needed to detect a given effect. Use it when designing experiments to ensure your study can reliably detect meaningful differences.
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
| Statistical Power Calculator | Birthday Paradox Calculator | |
|---|---|---|
| Category | Probability | Probability |
| Inputs required | 4 | 2 |
| Result | Statistical Power | Probability of Match |
| What it does | Calculates the statistical power of a hypothesis test or the sample size needed to detect a given effect. Use it when designing experiments to ensure your study can reliably detect meaningful differences. | 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. |