Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Probability
Sample Size Calculator
Determine the minimum sample size needed for a survey or experiment given your confidence level, margin of error, and population size. Prevents under-powered studies and over-budgeted data collection.
Fill in the required fields to see your result.
Probability
Bayes' Theorem Calculator
Compute the posterior probability P(A|B) using Bayes' theorem. Use it when you want to update a prior belief about event A after observing new evidence B β common in medical testing, spam filtering, and risk analysis.
Fill in the required fields to see your result.
Key differences
| Sample Size Calculator | Bayes' Theorem Calculator | |
|---|---|---|
| Category | Probability | Probability |
| Inputs required | 4 | 3 |
| Result | Required Sample Size (samples) | P(A|B) Posterior Probability |
| What it does | Determine the minimum sample size needed for a survey or experiment given your confidence level, margin of error, and population size. Prevents under-powered studies and over-budgeted data collection. | Compute the posterior probability P(A|B) using Bayes' theorem. Use it when you want to update a prior belief about event A after observing new evidence B β common in medical testing, spam filtering, and risk analysis. |