Z Score Calculator

What is the Z Score?

Z-score is a statistical measurement that describes a value's relationship to the mean of a group of values. Z-score is measured in terms of standard deviations from the mean.

If a Z-score is 0, it indicates that the data point's score is identical to the mean score. A Z-score of 1.0 would indicate a value that is one standard deviation from the mean. Z-scores may be positive or negative, with a positive value indicating the score is above the mean and a negative score indicating it is below the mean.

Z Score Formula

• Z denotes to sample Z Score
• X is the data point's
• µ is the population mean
• σ is the population standard deviation

Population Z Score formula

• σ denotes to population Z Score
• N is the number of observations
• x_i is the observed values of the population item
• μ is the mean value of the population