The Excel STANDARDIZE function returns a normalized (z-score) value from a distribution defined by its mean and standard deviation — how many standard deviations a value sits above or below the mean.
Syntax
| Argument | Description | |
|---|---|---|
x | Required | The value you want to normalize. |
mean | Required | The arithmetic mean of the distribution. |
standard_dev | Required | The standard deviation of the distribution. Must be greater than 0. |
How to use it
STANDARDIZE converts a raw value into a z-score using the formula (x - mean) / standard_dev. The result tells you how many standard deviations the value lies from the mean.
A positive z-score is above the mean, a negative one below, and 0 sits exactly at the mean. Z-scores let you compare values from distributions with different scales on a common footing.
standard_dev must be positive. If you pass a standard deviation of 0 or less, STANDARDIZE returns a #NUM! error.
Try it: interactive demo
Pick a STANDARDIZE example to see the formula and its result.
Practice workbook
Frequently asked questions
What is a z-score?
(x - mean) / standard_dev. A z-score of 2 means the value is two standard deviations above the mean.Why would I standardize a value?
What does a negative result mean?
What causes a #NUM! error?
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