Statistics Utility
Z Score Calculator
Calculate a z score from a raw value, mean, and standard deviation.
Calculate z score
Formula
z = (x − mean) ÷ standard deviation.
Worked example
If x = 85, mean = 80, and standard deviation = 5, then z = (85 − 80) ÷ 5 = 1.
Privacy
The calculation runs locally in the browser.
Limitations
A z score is arithmetic relative to a mean and standard deviation. This tool does not determine whether a normal-distribution model is appropriate and does not provide statistical inference.
For organizations
If you operate a website, learning resource, agency project, or developer platform and want to evaluate this utility as a maintained embed, see education use cases. PTH Embed is currently a controlled beta with selective qualified tools and aggregate usage metering.