Google Sheets CHIDIST Function: Syntax, Examples & Tips

What Is CHIDIST?

CHIDIST returns the right-tailed probability of the chi-square distribution: the chance that a chi-square variable with the given degrees of freedom exceeds x. In a chi-square test, that probability is the p-value.

CHIDIST is a legacy function. Google Sheets keeps it so older spreadsheets, including files imported from early versions of Excel, keep working. Its modern equivalent is CHISQ.DIST.RT, which takes the same arguments and returns the same value. New sheets should use CHISQ.DIST.RT, whose name makes the right-tail behaviour clear.

A Quick Chi-Square Refresher

The chi-square distribution describes the sum of squares of independent standard normal variables. It only takes non-negative values, is skewed to the right, and has one parameter: degrees of freedom. With few degrees of freedom the curve is bunched near zero with a long right tail; as degrees of freedom grow, it shifts right and becomes more symmetric. Its mean equals the degrees of freedom.

In practice you meet it most often in hypothesis tests: goodness-of-fit tests (does observed data match an expected pattern?), tests of independence in contingency tables (are two categories related?), and tests about a variance.

How CHIDIST Works

CHIDIST takes a non-negative statistic and the degrees of freedom and returns the area under the chi-square curve to the right of that statistic. A large statistic means a small tail area, which is evidence against the null hypothesis.

Note the direction: the name sounds like a general distribution function, but CHIDIST is right-tailed. The left-tailed version is CHISQ.DIST with cumulative set to TRUE. This is the most common source of confusion with the legacy name.

Basic Examples

Classic 5% threshold

=CHIDIST(3.841, 1)

Returns about 0.05.

p-value for a goodness-of-fit test

=CHIDIST(B8, COUNT(B2:B6)-1)

With the statistic in B8 and five categories, uses 4 degrees of freedom.

Same answer, modern function

=CHISQ.DIST.RT(3.841, 1)

Returns the same result as the first example.

Left tail from CHIDIST

=1 - CHIDIST(5, 3)

Gives the left-tailed probability, equal to CHISQ.DIST(5, 3, TRUE).

Legacy and Modern Names

Common Use Cases

• Maintaining older workbooks: understanding formulas written years ago
• Hypothesis tests: p-values for goodness-of-fit and independence statistics
• Teaching: matching textbook formulas that use the older name

Common Errors

• #NUM!: x is negative or degrees_freedom is less than 1.
• #VALUE!: An argument cannot be read as a number.
• Assuming a left tail: CHIDIST is right-tailed. Using it where a cumulative probability is needed gives 1 minus the right answer.
• Wrong degrees of freedom: Check whether your test calls for categories − 1 or (rows − 1) × (columns − 1).

Tips and Best Practices

• When editing an old sheet, consider swapping CHIDIST for CHISQ.DIST.RT; the result will not change.
• Pair with IF to label results significant or not at a chosen level.
• To work in the other direction, from probability to statistic, use CHIINV or CHISQ.INV.RT.

Related Functions

• CHISQ.DIST.RT: right-tailed probability (p-value)
• CHIINV: legacy inverse right-tailed function
• CHITEST: legacy chi-square test
• CHISQ.DIST: left-tailed probability or density
• IF: turn a p-value into a decision