## Summary

The Excel STANDARDIZE function returns a normalized value, or z-score, from a distribution characterized by the mean and standard deviation.

## Syntax

=STANDARDIZE (x, mean, standard_dev)

## Syntax Breakdown

X
Required. Value you want to normalize.

Mean
Required. Arithmetic mean. See the AVERAGE function to calculate the arithmetic mean.

Standard Dev
Required. Standard deviation of the distribution. See the STDEV.P function to calculate the standard deviation.

The function returns the #NUM! error if the standard_dev arguments is <= 0 (zero).

## Usage Notes

STANDARDIZE returns a normalized value, or z-score, based on the mean and standard deviation. The mean can be calculated using the AVERAGE function. Standard_dev can be found using the STDEV.P function.

Understanding Z-Scores
The z-score measures the number of standard deviations a data point is from the mean. It is means by which you can standardize scores on the same scale by dividing a score's standard deviation by the standard deviation of the data set. Z-scores are also known as standard scores.

To calculate a z-score, you first need to calculate the mean, using the AVERAGE function, and standard deviation, using the STDEV.P function.

Z-scores can be either negative or positive. If negative, it indicates that the value is less than the mean. Alternatively, a positive z-score indicates the value is greater than the mean. The average of every z-score for a given data set is 0 (zero).