BETALN in LibreOffice Calc: Availability and Alternatives

• First introduced: Not established. The former legacy/version claim was unsupported and has been withdrawn.
• Current status: Unsupported under this name in the verified release inventory. This is not a claim that the function was once supported and then retired.
• Last supported version / retirement: Unknown; no documented historical endpoint was found.
• Platform and edition scope: English function names in desktop Calc, including its bundled analysis/date/pricing add-ins. A third-party extension may register additional names but is not evidence for native support.
• Native testing: A representative imported-XLSX call returned #NAME? in LibreOfficeDev 26.8.0.0.alpha0 (build 2c87e51eeaa2b413ff4ae097b2705eea1995d8e5). The replacement examples below have independent expected results; selected principal examples were also cross-checked in that development build. This does not establish behavior in every stable version.
• Evidence checked: 2026-10-14.

The complete source check covered the built-in function registry, English names, analysis add-ins, date add-ins and pricing add-ins. Absence from one abbreviated web index alone was not used as proof.

For positive a and b, the logarithm of the mathematical beta function is:

=GAMMALN(a)+GAMMALN(b)-GAMMALN(a+b)

Here a and b are placeholders for numeric values or cell references; do not type them as names unless you defined named ranges. Enter 2 in A2 and 5 in B2, then use:

=GAMMALN(A2)+GAMMALN(B2)-GAMMALN(A2+B2)

Expected result: approximately -3.40119738166216. In this example Beta(2,5)=1/30 and its natural logarithm is ln(1/30). The logarithm is negative because 1/30 is below 1, not because the input is invalid.

Products and ratios of gamma functions can overflow even when a derived result is manageable. Working with GAMMALN avoids first calculating those large gamma values. It does not promise unlimited numeric range or perfect cancellation accuracy for extreme parameters. Validate results against a known small example before extending a statistical model to large values.

If the ordinary beta value is required, =EXP(C2) converts a log-beta result in C2 back to the original scale. For the example it is approximately 0.0333333333333333. Keeping the log result is preferable when later calculations will add log-probabilities rather than multiply very small probabilities.

This replacement is stated for positive a and b. Do not use it as an undocumented analytic continuation to non-positive or complex inputs. Check types, signs and parameter meaning before applying it. A beta-distribution density is a separate calculation; use BETA.DIST with the appropriate cumulative flag for that purpose.

The original BETALN calls have been replaced with the supported expression rather than relabeled as a retired feature.

• GAMMALN in LibreOffice Help