FINV Function (Gnumeric)

• Introduced: First release not established; this name is present in the tested Gnumeric 1.12.57 and the cited 1.12.62 source.
• Availability: Supported in Gnumeric 1.12.62 according to its function-specific registration. No retirement endpoint is established.
• Scope: Desktop Gnumeric with the fn-stat module enabled. Examples use English comma-separated formulas.
• Checked: October 14, 2026. Reference and boundary tables were recalculated by Gnumeric 1.12.57 and checked independently. The 1.12.62 contract was source-checked, not executed.

The cutoff x satisfies FDIST(x,d1,d2)=p. A small upper-tail probability produces a large cutoff. This is an inverse cumulative-tail operation, not a reciprocal such as 1/FDIST. Official FINV reference.

=FINV(p,dof_of_num,dof_of_denom)

All arguments shown are required. Use numeric cells or numeric inputs. The formulas use decimal points and commas; localized entry conventions require separate checks. Gnumeric 1.12.62 help and evaluator.

Enter each formula in a separate cell. The displayed references are rounded to twelve decimal places and agree with the recorded Gnumeric 1.12.57 recalculation within ordinary floating-point precision. Keep the stored result for subsequent calculations.

Put upper-tail probability 0.05 in A2 and degrees of freedom 5 and 5 in B2:C2. =FINV(A2,B2,C2) gives the first cutoff in the table. Check it with =FDIST(FINV(A2,B2,C2),B2,C2), expected approximately 0.05.

Keep the probability as a fraction: 5% means 0.05, while the number 5 is outside the domain. A cutoff is a statistic value, so format it as a number rather than a percentage.

Construct two percentile cutoffs without reversing the model

For a central 95% reference interval with degrees of freedom 5 and 5, use lower cutoff =FINV(0.975,5,5) and upper cutoff =FINV(0.025,5,5). The larger right-tail probability produces the lower cutoff. These probabilities are deliberately reversed relative to a left-tail inverse.

The reciprocal identity is FINV(p,d1,d2)=1/FINV(1−p,d2,d1) for interior probabilities. For example, compare =FINV(0.2,2,4) with =1/FINV(0.8,4,2). Pre-specify the variance-ratio orientation in an application; changing it after seeing the samples is not merely a display preference.

The tested release returns 0 at p=1 and #NUM! at p=0, where the finite cutoff does not exist. The wrapper rejects probabilities outside [0,1] and degrees of freedom below 1; it floors both degrees of freedom. Do not label p=0 as an ordinary very-large result or silently replace an error with an arbitrary cap.

The following are observed cell results from the same 1.12.57 command-line recalculation. F5 was genuinely empty. A blank is not necessarily an omitted argument or a valid observation, so validate required data instead of treating every defaulted zero as intentional.

The fixtures do not certify every locale, extreme tail, imported type or newer binary build. The current wrapper agrees with the documented argument contract; shared numerical helpers can change between releases.

• FDIST
• FTEST
• FINV official manual entry
• Version-pinned argument contract and calculation
• Nonfinite numeric results