Z-Score Calculator

How many standard deviations a value is from the mean.

Result

Z-score

2.00

How it works

z = (value − mean) ÷ standard deviation

The z-score standardizes a value: it tells you how far it sits from the average, in units of standard deviation. z = 0 is exactly average; z = 2 is well above.

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Frequently asked questions

What does a z-score mean?

It is the distance from the mean in standard deviations — positive is above average, negative below.

What z-score is unusual?

Roughly |z| > 2 covers only ~5% of a normal distribution, so it is considered uncommon.

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