CHIDIST Function (Calligra Sheets)

• Introduced: First release not established; the name is present in Calligra 2.4.0 source.
• Supported in: Calligra Sheets 26.08.2, with no retirement established.
• Scope: Desktop Sheets with the Statistical module. Examples use English semicolon-separated formulas.
• Checked: October 14, 2026. Selected formulas ran through the official 25.04.2 engine library. Source and independent mathematics were checked. This is engine evidence, with no GUI-cell or import verification; 26.08.2 was source-checked only.

CHIDIST returns the right-tail chi-square probability P(X>x). For two degrees of freedom it reduces to exp(−x/2) at positive x. It is not the left-tail cumulative probability and does not return the chi-square density. Function help.

=CHIDIST(x;degreesFreedom)

Exactly two arguments are required. The wrapper accepts degreesFreedom from 1 inclusive to 100000 exclusive. It does not floor the degrees of freedom before passing half that value to the gamma-distribution helper. Nonpositive x returns 1. Use finite numeric inputs and validate their statistical meaning independently of that endpoint convention. Registration and implementation.

The engine and mathematical columns are separate. Results are rounded to twelve decimal places, or thirteen significant digits in scientific notation for very small or large values. This is a display choice, not an accuracy guarantee. NaN and infinity are nonfinite outputs; an engine error flag is checked separately from those values.

For x=5.3 and two degrees of freedom, the mathematical upper-tail probability is approximately 0.070651213060. The separately retained engine result differs in later digits. For a right-tail test with those specified degrees of freedom, the probability is the area above the observed statistic, not the probability that a hypothesis is true.

A worksheet can place the statistic in A2 and degrees of freedom in B2, then use =CHIDIST(A2;B2). The valid degrees of freedom must come from the model or test design; this function does not determine them from a data table.

The independent identity CHIDIST(2,2)=exp(−1) gives a transparent accuracy check. The executed difference in the displayed composition is about 3.88×10^−11 rather than exactly zero. That residual is retained because the source computes through an approximate gamma helper.

The mathematical left-tail probability is 1−CHIDIST(x,df). A central interval requires two separately chosen tail cutoffs; a single right-tail value is not a two-tailed test. For extreme tails, subtraction can also lose relative precision, so these modest examples do not establish arbitrary-tail accuracy.

The executed advanced check was:

=CHIDIST(2;2)-EXP(-1)

Its engine result was 3.883827835076E-11.

The accepted upper region is not uniformly numerically safe: CHIDIST(2;99999) produced NaN with no engine error flag. The adjacent excluded df=100000 produced #VALUE!. These are distinct outcomes. Invalid text for x was converted to zero in the tested call and therefore returned 1, which must not be treated as successful validation of a statistic.

• Function-specific implementation
• Versioned function help
• Gamma Dist helper

The statistical module and value-calculation helpers are byte-identical between the inspected 25.04.2 and 26.08.2 sources. That comparison supports the source discussion but does not establish later-version native output, every locale or arbitrary extreme-parameter accuracy.

NORMDIST.