The Excel NORMINV function returns the inverse of the normal cumulative distribution — given a probability, it finds the x value. It is a legacy function; Microsoft replaced it in Excel 2010 with NORM.INV, which takes the same arguments.
Syntax
| Argument | Description | |
|---|---|---|
probability | Required | A probability associated with the normal distribution, between 0 and 1. |
mean | Required | The arithmetic mean of the distribution. |
standard_dev | Required | The standard deviation of the distribution (must be > 0). |
How to use it
NORMINV is the reverse of NORMDIST (cumulative form): supply a probability plus the mean and standard deviation, and it returns the x at which the cumulative normal distribution reaches that probability — the percentile value.
It is commonly used to find cut-off scores and confidence limits. Feeding the output of NORMDIST(...,TRUE) back into NORMINV returns your original x. The probability must be between 0 and 1.
Use NORM.INV in Excel 2010 and later. NORMINV is kept only for backward compatibility. Microsoft recommends NORM.INV, which has the same three arguments.
Try it: interactive demo
Pick a NORMINV example to see the formula and its result.
Practice workbook
Frequently asked questions
Should I use NORMINV or NORM.INV?
NORM.INV in Excel 2010 or later — it takes the same probability, mean, standard_dev arguments and is the supported function. NORMINV is kept only for older workbooks.How does NORMINV relate to NORMDIST?
NORMDIST(x,mean,sd,TRUE) turns an x into a probability; NORMINV(probability,mean,sd) turns that probability back into x.What value does NORMINV(0.5, ...) return?
mean, because the normal distribution is symmetric and its median equals its mean.What range must the probability be in?
probability argument must be between 0 and 1 (exclusive of 0 and 1). Values outside that range, or non-numeric inputs, return an error.Master functions like this in one day
This page covers one function. Our Excel Formulas and Functions class covers the 30 that matter most — live, hands-on, taught by professionals in Dallas–Fort Worth, Houston, Austin, Oklahoma City, Denver, or online.
See the Formulas & Functions Class