Z-Score Calculator
Standardize a value relative to a distribution’s mean and standard deviation for comparison across scales.
Z-score1.25
Distance from mean1.25 standard deviations
How this tool works
z=(x−μ)/σ. Positive z is above the mean; negative z is below it.
Example
A score of 85 in a distribution with mean 75 and standard deviation 8 has z=1.25.
Common questions
What does z=0 mean?
The value is exactly equal to the mean.
Can standard deviation be zero?
A zero standard deviation means all values are identical, so a conventional z-score is undefined.