Syntax
NORMINV(probability, mean, standard_dev)
| Parameter | Description |
|---|---|
| probability | Parameter of the NORMINV function. |
| mean | Parameter of the NORMINV function. |
| standard_dev | Parameter of the NORMINV function. |
Examples
95th percentile exam score
Formula
=NORMINV(0.95, 75, 10)
Returns 91.45. In a class where scores average 75 with std dev 10, 95% of students scored below about 91.5.
Lower 10% cutoff for quality control
Formula
=NORMINV(0.10, 500, 25)
Returns 467.96. Parts weighing below ~468g fall in the bottom 10% and may be rejected.
Median of a normal distribution
Formula
=NORMINV(0.5, 100, 15)
Returns 100. The median of a normal distribution equals the mean.
Common Errors
#NUM!
Probability must be between 0 and 1 (exclusive). A value like 1.5 or -0.1 triggers this error.
#VALUE!
Occurs if any argument is non-numeric, such as passing text where a number is expected.
Tips
Use for confidence intervals
Pair NORMINV with your data's mean and standard deviation to calculate confidence interval bounds, e.g., NORMINV(0.025, mean, std) for the lower 2.5% bound.
Upgrade to NORM.INV
NORMINV is the legacy version. NORM.INV is the modern replacement with identical behavior but better consistency with other .DIST/.INV functions.
Standard normal shortcut
For a standard normal (mean=0, std=1), use NORM.S.INV instead to save typing two arguments.
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