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Both calculators run independently — change the inputs on either side to compare results.
Statistics
Confidence Interval Calculator
Compute the lower and upper bounds of a confidence interval for a population mean using a sample mean, the standard error of that mean, and a critical z-value (1.645 / 1.96 / 2.576 for 90% / 95% / 99% confidence). This is the standard way to report uncertainty around survey results, lab measurements, or any sample-based estimate.
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
| Confidence Interval Calculator | Z-Score Calculator | |
|---|---|---|
| Category | Statistics | Statistics |
| Inputs required | 3 | 3 |
| Result | Lower Bound | Z-Score |
| What it does | Compute the lower and upper bounds of a confidence interval for a population mean using a sample mean, the standard error of that mean, and a critical z-value (1.645 / 1.96 / 2.576 for 90% / 95% / 99% confidence). This is the standard way to report uncertainty around survey results, lab measurements, or any sample-based estimate. | 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. |