A z-score tells you how many standard deviations away an individual data value falls from the mean. It is calculated as:

z-score = (x – μ) / σ

where:

This calculator allows you to compare the relative standing of two data points using their z-scores. Simply fill in the boxes below and then click the “Calculate” button.

μ₁ (population 1 mean)

σ₁ (population 1 standard deviation)

x₁ (individual value 1)

μ₂ (population 2 mean)

σ₂ (population 2 standard deviation)

x₂ (individual value 2)

z-score of first value = (19–15) / 4.2 = 0.9524

z-score of second value = (17–14) / 2.6 = 1.1538