NORMINV in Calligra Sheets: Normal Percentiles and Thresholds

• Introduced: First release not established. The name is registered in Calligra 2.4.0, which proves historical presence, not introduction.
• Availability: Supported in Calligra Sheets 26.08.2, according to the release-pinned registration.
• Scope: Desktop Sheets with the statistical functions module available. Names and separators can depend on locale.
• Checked: October 14, 2026. Official documentation/source and independent mathematical examples checked; Calligra was not run.

NORMINV converts a left-tail cumulative probability into an x-value, using a chosen mean and positive standard deviation. It returns a measurement threshold, not a density or a percentage. KDE function handbook.

The mathematical relationship is x=μ+σΦ⁻¹(p). Φ denotes the standard-normal cumulative distribution. These formulas describe an assumed probability model; successful calculation does not establish that a normal distribution fits a real dataset.

=NORMINV(Number; MV; STD)

All listed arguments are required; there is no documented default to substitute for an omitted input. Use semicolons as shown in the English KDE examples, decimal points in the sample data, and the separators accepted by your installation. Release-pinned function help.

Enter the numeric inputs into the stated columns, then enter the indicated result formula. Fill through row 12. The expected results are mathematical references rounded to twelve decimal places; a displayed probability used as a new input can differ slightly from its unrounded original.

Find a central 95% model interval

For mean 100 and standard deviation 10, calculate:

=NORMINV(0.025;100;10)
=NORMINV(0.975;100;10)

The expected endpoints are 80.400360154599 and 119.599639845401. Each tail contains 2.5%, leaving 95% between them. These are distribution quantiles under assumed parameters, not a confidence interval for an estimated mean and not a guarantee about future observations.

Check a cutoff by converting it back

Put probability 0.9 in A2, mean 100 in B2 and SD 10 in C2. In D2 enter =NORMINV(A2;B2;C2). Then =NORMDIST(D2;B2;C2;1) should return approximately 0.9. Use the full cell value rather than retyping a rounded cutoff.

The release rejects STD≤0 and probabilities outside the open interval 0<p<1 with an internal value-error object. Endpoints 0 and 1 correspond to unbounded normal quantiles; they are not finite cutoffs. Enter 0.9 or a numeric 90%, not the number 90. Release computation and guards.

Sensitivity increases near either probability endpoint. Since dx/dp=σ/φ(Φ⁻¹(p)), a small probability change in a thin tail can move the cutoff considerably. Keep enough input precision and avoid claiming more accuracy than the fitted mean and standard deviation justify.

An internal Value::errorVALUE() in the source identifies the error category, not a guarantee of the same visible token in every package or locale. Validate numeric input cells and units rather than depending on implicit text or blank-cell conversion.

NORMDIST supplies the general normal CDF or density; NORMINV reverses its CDF. NORMSDIST and NORMSINV use mean zero and standard deviation one. Follow each function’s own argument contract instead of adding or omitting a flag by analogy.

Other spreadsheet programs may use dotted names such as NORM.DIST or NORM.S.INV. A related mathematical name does not prove that an imported formula, error display or locale separator transfers unchanged. Validate the actual target workbook when exchanging files.

• NORMINV handbook entry
• Calligra 26.08.2 syntax and argument help
• Release-pinned calculation and domain guards