Z Score Calculator
Result
Formula: z = (value − mean) / standard deviation.
Worked example: For x=85, mean=70, SD=10: z=(85−70)/10=1.5; x=60 gives z=−1.
Primary source: OpenStax Introductory Statistics, z scores. The linked text describes the mathematical definition or method used.
How to use this tool
Enter the numbers and choose Calculate to compute z score. Results are calculated in this browser.
Frequently asked questions
What does this calculator compute?
Free z-score calculator: enter a value, the mean and the standard deviation to see how many standard deviations it sits from the mean, with the formula.
Where do the inputs go?
The calculation runs in this browser; the page does not submit the entered values.
What formula is used?
The result displays the formula used: z = (value − mean) / standard deviation.