The Excel BETAINV function returns the inverse of the cumulative beta distribution — the value of x for a given probability. It is the legacy form of BETA.INV, introduced in Excel 2010.
Syntax
| Argument | Description | |
|---|---|---|
probability | Required | A probability associated with the beta distribution (between 0 and 1). |
alpha | Required | The first shape parameter of the distribution (must be > 0). |
beta | Required | The second shape parameter of the distribution (must be > 0). |
A | Optional | The lower bound of the interval for x. Defaults to 0. |
B | Optional | The upper bound of the interval for x. Defaults to 1. |
How to use it
BETAINV answers the reverse question to BETADIST: given a cumulative probability, what value of x produces it? The two functions are exact inverses on the same interval.
The optional A and B rescale the result to your interval; omit them for the standard 0–1 range. Feeding the output of BETADIST back into BETAINV (or vice versa) returns the original input.
Use BETA.INV instead: the modern =BETA.INV(0.685,8,10,1,3) returns the same value with identical arguments. BETAINV is kept only so older workbooks keep calculating.
Try it: interactive demo
Pick a BETAINV example to see the formula and its result.
Practice workbook
Frequently asked questions
What is the modern replacement for BETAINV?
BETA.INV, added in Excel 2010, with the same arguments. =BETA.INV(0.685,8,10,1,3) equals =BETAINV(0.685,8,10,1,3).How does BETAINV relate to BETADIST?
What range must the probability be in?
Why use BETAINV in practice?
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