The Excel NORM.S.DIST function returns the standard normal distribution — the bell curve with mean 0 and standard deviation 1 — for a given z-score, as either a cumulative probability or a density.
Syntax
| Argument | Description | |
|---|---|---|
z | Required | The z-score (value) at which to evaluate the standard normal distribution. |
cumulative | Required | TRUE returns the cumulative distribution (area to the left of z); FALSE returns the probability density at z. |
How to use it
NORM.S.DIST is NORM.DIST locked to the standard normal curve — mean 0, standard deviation 1 — so you only pass a z-score and the cumulative flag.
With TRUE you get the familiar z-table value — the proportion of the curve to the left of z. NORM.S.DIST(0,TRUE) is exactly 0.5, since half the curve lies left of the mean.
From raw value to z-score: standardize first with STANDARDIZE(x, mean, sd) (or (x-mean)/sd), then feed the z into NORM.S.DIST. The inverse direction is NORM.S.INV.
Try it: interactive demo
Pick a NORM.S.DIST example to see the formula and its result.
Practice workbook
Frequently asked questions
What is a z-score?
What is the difference between cumulative TRUE and FALSE?
TRUE returns the cumulative probability (area to the left of z) — the classic z-table number. FALSE returns the probability density, the height of the standard normal curve at z.How does NORM.S.DIST relate to NORM.DIST?
NORM.S.DIST(z,TRUE) equals NORM.DIST(z,0,1,TRUE).Did NORM.S.DIST replace an older function?
NORMSDIST, and unlike the old single-argument version it adds a cumulative flag so it can return the density too.Master functions like this in one day
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