FINV 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.

FINV returns a numerical inverse of Calligra’s left-tail FDIST. Probability p is the area below the requested cutoff. It does not use the traditional right-tail FINV convention found under the same legacy name in some other products. Function help.

=FINV(probability;numeratorDF;denominatorDF)

Exactly three arguments are registered. Use 0<p<1, numeratorDF≥1 and denominatorDF≥1, each below the FDIST helper’s 10^10 guard. Fractional degrees are retained. The commented-out validation in the wrapper is not an active check, so syntax acceptance cannot establish domain validity. 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 degrees 2 and 2, the CDF is x/(1+x), so the quantile is p/(1−p). The 75th percentile is 3 and the 95th percentile is 19. These transparent examples establish the left-tail interpretation.

For a right-tail probability q strictly between 0 and 1, the mathematical cutoff corresponds to lower-tail probability 1−q. State that transformation explicitly; simply passing q reverses the intended tail. A worksheet should check probability and degree inputs before calling the inverse.

The executed FDIST(FINV(0.9;5;10);5;10) composition returns approximately 0.900000000000. It is an internal roundtrip through the same helper, so an independent quantile reference remains valuable. The table supplies both engine and mathematical results.

The solver expands a search interval and then uses bisection with a final interpolation step. Its fixed stopping rule and the approximate cumulative helper can leave discrepancies in later digits. Printing twelve decimals is a display convention, not a claim of twelve-decimal mathematical accuracy.

The executed advanced check was:

=FDIST(FINV(0.9;5;10);5;10)

Its engine result was 0.9.

The diagnostic p=1 returned 18014398509481984, although the upper endpoint of an F distribution is unbounded. The outside-domain p=1.1 returned 36028797018963968, and p=−0.1 returned 0. Invalid degree cases also returned zero. These are recorded failure behaviors, not useful quantiles. Missing or excess arguments are still rejected by registration.

• Function-specific implementation
• Versioned function help
• Inverse helper
• Beta 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.

NORMINV.