How to Calculate Z Score

A step by step z score tutorial to know how to find the z score in statistics with an example problem.

Finding Z score | Standard Score Formula

Z Score is also called as Standard Score. Z Value Calculator allows you to determine how many number of standard deviation is above or below the population mean a raw score is. By knowing the mean, variance and standard deviation, you can easily find the Z score of the sample. Z score can also be placed in the Normal Distribution Curve. It is a dimensionless quantity obtained by finding the difference between the sample and mean, and dividing the resulting value by standard deviation. Learn here how to calculate z score in statistics with the standard score formula and example.

Standard Score Formula:
Finding Z score is very simple. Use the basic formula provided below to calculate the Z score of any statistics.
z = (x - μ) / σ
x - value of an element
μ - population mean
σ - standard deviation

Z Score Example:
An individuals test score is 250. The mean is 200 and has standard deviation 30. What is the Z score.
Click on the below links to learn how to calculate Mean and Standard Deviation.
Step 1:
Given,
Test score (X) - 250
Mean (μ) - 200
Standard Deviation (σ ) - 30

Step 2: Substitute the values in the formula.
z = (x - μ) / σ
= (250 - 200)/30
= 50 / 30
= 1.6
The Z Score value is 1.6.

Use our Z value calculator to calculate the z-value from the standardized random variable, sample mean and the sample standard deviation.

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