Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Statistics
Sample Size Calculator
Calculate the minimum number of respondents needed to estimate a population proportion within a given margin of error at a chosen confidence level — the standard formula behind almost every survey, poll, and quality audit. Includes the finite-population correction so you can plan surveys of small populations without over-sampling.
Fill in the required fields to see your result.
Statistics
Z-Score Calculator
Convert any raw value into a z-score — the number of standard deviations it sits above or below the mean of its distribution. Used everywhere from standardised test reporting and quality control to risk modelling and machine-learning feature scaling.
Fill in the required fields to see your result.
Key differences
| Sample Size Calculator | Z-Score Calculator | |
|---|---|---|
| Category | Statistics | Statistics |
| Inputs required | 3 | 3 |
| Result | Required Sample Size | Z-Score |
| What it does | Calculate the minimum number of respondents needed to estimate a population proportion within a given margin of error at a chosen confidence level — the standard formula behind almost every survey, poll, and quality audit. Includes the finite-population correction so you can plan surveys of small populations without over-sampling. | Convert any raw value into a z-score — the number of standard deviations it sits above or below the mean of its distribution. Used everywhere from standardised test reporting and quality control to risk modelling and machine-learning feature scaling. |