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Z-score calculator
Enter a raw score, the mean and the standard deviation. You get the z-score, the percentile it corresponds to, and the proportion of the distribution above and below it.
If your data is skewed, the z-score is still correct as a standardised distance, but the percentile it implies will not be. Check the distribution before quoting a percentile.
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This calculator was checked by Tara Sutaria, Senior Statistical Analyst
In short
What is a z-score?
A z-score expresses how many standard deviations a value lies from the mean of its distribution. It is calculated as (value − mean) ÷ standard deviation. A z of 0 is exactly average, +1 is one standard deviation above the mean, and about 95% of a normal distribution falls between −1.96 and +1.96.
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