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How to use Z-Score Calculator

Enter the value x, the mean μ and the standard deviation σ, and the calculator returns the z-score and its approximate percentile.

Frequently asked questions

What is a z-score?

The number of standard deviations a value lies from the mean: z = (x − μ) / σ.

What does a negative z-score mean?

It means the value is below the mean; a positive z-score means it is above the mean.

What is the percentile output?

An approximate percentage of a normal distribution that falls below your value, derived from the z-score.

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