Z-Score Calculator

Standardize a value, see how many standard deviations it is from the mean, and estimate its normal-distribution percentile.

Mode

Mean (μ)

Standard deviation (σ)

Raw score (x)

—Result

—Percentile / left tail

—Right tail

—Two-tail beyond |z|

—Normal-distribution probabilities are also shown.

How to use this Z-Score Calculator

Calculate a z-score from a value, mean, and standard deviation. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.