Z-Score Calculator

Calculate z-scores for single values or entire datasets, with percentile and probability interpretation.

Single Value Z-Score

Value (X)

Mean (μ)

Std Dev (σ)

Dataset Z-Scores

Data (one value per line)

Z-Score: Measures how many standard deviations a value is from the mean. A z-score of 0 means the value equals the mean; positive values are above the mean, negative below.