Summary

NORM.DIST returns the normal distribution for a value when you know the mean and standard deviation. It is used when you want to model values on a bell curve.

The most important choice in this function is the last argument. With TRUE, you get the cumulative distribution, which is the probability up to that point. With FALSE, you get the probability density at that point.

Syntax

=NORM.DIST(x, mean, standard_dev, cumulative)

x is the value you are checking, mean is the center of the distribution, standard_dev controls the spread, and cumulative chooses the form of the result.

Arguments

• x - [required] The value to evaluate.
• mean - [required] The arithmetic mean of the distribution.
• standard_dev - [required] The standard deviation of the distribution.
• cumulative - [required] Use TRUE for cumulative probability and FALSE for probability density.

NORM.DIST vs Other Functions

Using the NORM.DIST Function

In most business or classroom work, the cumulative form is the one people use more often. It helps answer questions like “What is the probability of being at or below this score?” If you want the probability above a value, a common pattern is 1-NORM.DIST(x,mean,standard_dev,TRUE).

Microsoft notes that if mean or standard_dev is not numeric, Excel returns #VALUE!. If standard_dev is less than or equal to zero, Excel returns #NUM!. Microsoft also notes that when mean=0, standard_dev=1, and cumulative is TRUE, the function matches NORM.S.DIST.

The FALSE version is a density, not the probability of one exact value happening in a discrete sense. That distinction matters, so for plain-language probability questions, the TRUE version is usually the easier one to interpret.

Example 1 - Return the density at one point

This is the non-cumulative version of the function.

=NORM.DIST(85,80,10,FALSE) // Returns the density value at x = 85.

Example 2 - Return the cumulative probability up to one point

This is the version people usually want for probability questions.

=NORM.DIST(85,80,10,TRUE) // Returns the cumulative probability up to 85.

Example 3 - Check how typical a measurement is

A bell-curve model can help you compare one value against a typical range.

=NORM.DIST(180,175,7,FALSE) // Returns the density value for 180 in that distribution.

Example 4 - Find the probability above a target

Subtract the cumulative result from 1 when you want the upper tail.

=1-NORM.DIST(95,80,10,TRUE) // Returns the probability above 95.

Conclusion Recap

• Main job: NORM.DIST returns the normal distribution for a value.
• TRUE vs FALSE matters: TRUE gives cumulative probability, while FALSE gives probability density.
• Upper-tail probability: Use 1-NORM.DIST(...,TRUE) when you want the chance above a threshold.
• Standard deviation must be positive: Otherwise Excel returns #NUM!.
• Good fit: Use it for bell-curve modeling when you know the mean and standard deviation.
• Related option: Use NORM.S.DIST for the standard normal curve.