Z Score Calculator

Enter raw score, population mean, and standard deviation in the respective fields to calculate Z score using z table calculator.

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Z score formula

The following equations used to find the z statistics (score).

Z = (X – μ)/ σ

X is raw score,

μ is population mean, and

σ is standard deviation.

Use Z score calculator to find the Z-score value online. This tool applies the Z-score formula to calculate Z score for hypothesis testing. It also shows you step by step calculation for given data.

What is Z score?

A z-score or z-statistic is a result of implementing a z-test that tells us how far a raw score is from mean, when measured in standard deviation units. It represents a point from standard normal distribution (z chart).

Moreover, the critical value of a z score can be used to determine the margin of error.

  • The z-score is positive if the value is more than mean.
  • It is negative if value is less than mean.

How to calculate z score?

Wondering how to find z score? Let’s calculate it using an example.


Find the z-score for the given values.

Raw score = 70

Standard deviation = 8

Population mean = 12

Step 1: Write down the formula of Z-score.

Z = (X – μ)/ σ

Step 2: Place the values in the above equation.

Z = (70 – 12)/ 8

Z = 58/8 = 7.25