Standard Deviation Calculator vs Z-Score Calculator
Two calculators for the same neighbourhood of questions. Here is what each measures, what you feed in, and where you'd reach for one over the other.
Standard Deviation Calculator
Compute the sample standard deviation directly from three summary statistics — sample size n, the sum of values Σx, and the sum of squared values Σx². This is the spread metric used in virtually every empirical study, quality-control chart, and risk model.
- Answers
- Standard Deviation
- Inputs
- Sample Size, Sum of Values, Sum of Squares
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.
- Answers
- Z-Score
- Inputs
- Value (X), Mean (μ), Standard Deviation (σ)
At a glance
| Standard Deviation Calculator | Z-Score Calculator | |
|---|---|---|
| Category | Statistics | Statistics |
| Answers | Standard Deviation | Z-Score |
| Inputs | 3 | 3 |
| Result unit | — | — |
When to use each
Compute the sample standard deviation directly from three summary statistics — sample size n, the sum of values Σx, and the sum of squared values Σx². This is the spread metric used in virtually every empirical study, quality-control chart, and risk model.
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.