NORM.INV
Returns the inverse of the normal cumulative distribution.
=NORM.INV(probability, mean, standard_dev)This static page keeps the function indexed for search, while the spreadsheet app handles interactive exploration and saved formulas.
What the function does
Overview
Returns the inverse of the normal cumulative distribution.
The NORM.INV function calculates the inverse of the cumulative normal distribution for a specified mean and standard deviation. Mathematically, it determines the value x such that the area under the normal curve to the left of x equals the provided probability. This is a critical tool for statistical modeling, such as determining confidence intervals, calculating critical values for hypothesis testing, or identifying performance thresholds (e.g., the score needed to be in the top 10%). Best practices include validating that the probability argument is strictly between 0 and 1 (non-inclusive) and that the standard deviation is a positive value. For a standard normal distribution where the mean is 0 and the standard deviation is 1, NORM.S.INV is a more efficient alternative. Note that NORM.INV uses an iterative search technique to find the value, which may result in #NUM! errors if the algorithm fails to converge within 100 iterations.
Quick reference
Syntax
=NORM.INV(probability, mean, standard_dev)Inputs
Arguments
Example: 0.95
Example: 70
Example: 10
Formula patterns
Examples
Calculate 95th percentile exam score
=NORM.INV(A2, B2, C2)Find the lower 5% threshold for quality control
=NORM.INV(0.05, A3, B3)Dynamic boundary calculation for inventory levels
=NORM.INV(A4, B4, C4)Avoid these issues
Common Errors
#NUM!
Cause: The probability argument is less than or equal to 0 or greater than or equal to 1, or the standard_dev is less than or equal to 0.
Fix: Ensure the probability is a decimal between 0 and 1, and the standard deviation is a positive number.
#VALUE!
Cause: One or more of the arguments provided is non-numeric.
Fix: Check that the referenced cells (A2, B2, C2) contain numbers and do not contain text or invisible characters.
Platform support
Compatibility
Source: Microsoft Support
Common questions
Frequently Asked Questions
Returns the inverse of the normal cumulative distribution.
probability: Probability (0 to 1) mean: Distribution mean ev: Standard deviation
#NUM!: Ensure the probability is a decimal between 0 and 1, and the standard deviation is a positive number. #VALUE!: Check that the referenced cells (A2, B2, C2) contain numbers and do not contain text or invisible characters.