How To Find A Z Score

Also referred to as standard scores, z scores standardize on a uniform scale the data obtained from various measures and tests, enabling users to perform comparisons with the data. The points on a standard normal distribution, which is a bell curve that peaks at zero and has a standard deviation of one, correspond to z scores. As a result, a z score represents the number of standard deviations that a score is above or below the mean. Finding a z score involves performing a two-part calculation using three figures.

Step 1

Identify the raw score to be standardized, as well as the standard deviation and mean of the given data set.

Step 2

Subtract the mean from the raw score.

Step 3

Divide the difference obtained in the previous step by the standard deviation. The quotient is the z score.