Statistics

Z-score Calculator

Measure how far a value sits from the mean in standard deviation units.

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Input

Enter the value, the mean, and the standard deviation to measure the score in standardized units. You will see the result first and the step-by-step solution below.

Input summary

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Step by Step Calculation

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Calculate first and the full working will appear below automatically.

How to use Z-score Calculator

Type the observed value together with the mean and standard deviation, and the calculator will standardize the result.

What this calculator is for

This calculator is for statistics and test-score interpretation when you want to compare one observation to the rest of a distribution on a common scale.

Tips

A positive z-score means the value is above the mean; a negative score means it is below.
If the standard deviation is zero, the data have no spread and a z-score is not meaningful.
Use the same dataset basis for the value, mean, and standard deviation.