LOG Function in ONLYOFFICE Spreadsheet Editor: Base Choice, Syntax and Examples

The base determines the unit scale: base 10 counts powers of ten, base 2 counts powers of two. An omitted base is an intentional choice of 10 in ONLYOFFICE, not an unspecified implementation detail.

For x>0, b>0, b≠1: LOG_b(x)=LN(x)/LN(b). For integer b greater than 1, LOG(b^k,b)=k mathematically.

=LOG(number, [base])

The official reference explicitly gives base = 10 when omitted. Square brackets in documentation indicate optional notation; never type the brackets as literal formula characters.

The spelling, argument order and documented defaults above follow the ONLYOFFICE LOG function reference, accessed 2026-10-13. No argument-order assumptions were borrowed from another spreadsheet product.

1. Open a blank spreadsheet and select an empty result cell.
2. Type a formula beginning with =, or use Formula → Function, search for LOG, then enter the required arguments.
3. For the following examples, use the English function name, a decimal point, and commas where multiple arguments appear, matching ONLYOFFICE’s documented English formula examples.
4. Confirm the result, then use the cell’s number format to display six decimal places when comparing fractional expected values.
5. If a formula is rejected, check File → Advanced Settings for formula language and regional settings. ONLYOFFICE lets you change formula language and decimal/grouping separators; the exact punctuation for each locale has not been tested. Do not blindly replace commas with semicolons without checking the target installation.

Enter the following number/base pairs in A2:B7. In C2 type =LOG(A2,B2) and copy down where a base is supplied. For the row marked “omit base,” use =LOG(A5) instead. Format C2:C7 to six decimal places to compare with expected figures.

Verification method: table outputs above are numerical expectations computed independently with Python’s math library, formatted to six decimal places. They are not asserted as ONLYOFFICE screenshots, native execution results or exact display strings. The vendor’s reference verifies the formula form but not the sample rows.

The following formulas use literal numeric values, so they can be pasted into any blank result cell of a scratch workbook. Results are six-decimal mathematical expectations (unless the underlying calculation is an exact integer).

Avoid mistaking a displayed rounded value for exact mathematical equality. A visible 0.000000 may arise from cell formatting when the internal value is merely small.

For A2=100000, =LOG(A2) returns the base-10 exponent 5. For A2=100, =LOG(A2,2) returns approximately 6.643856; the same numeric input tells a different story in another base.

Bits required to encode a range of possibilities

If A2=1000 is the count of equally possible outcomes, enter:

=LOG(A2,2)

The expected information measure is 9.965784 bits (mathematical ideal, not a storage allocation). If you need a whole number of binary digits for IDs numbered 0 through 999, use =ROUNDUP(LOG(A2,2),0) → 10. The whole-number conclusion assumes every ID must fit, while the entropy interpretation assumes equally likely outcomes.

Change-of-base identity

=LN(A2)/LN(2) gives the same mathematical value as =LOG(A2,2) for positive A2. This identity is useful when comparing spreadsheets, but equivalence in a particular build still needs native execution verification.

Match LOG with LOG10 and LN

For A2=1000: =LOG(A2) (default base 10) and =LOG10(A2) both have expected output 3; =LN(A2) has expected output about 6.907755. No cross-editor result is assumed from this mathematical comparison.

Official LOG documentation confirms number > 0 and base 10 on omission, but does not state a first-supported version or enumerate all invalid-base errors. In real-number mathematics, an alternative base must be >0 and !=1. Do not present an expected #NUM! / #VALUE! or coercion rule as an observed ONLYOFFICE fact without native execution.

For a comparative spreadsheet tutorial, note that other spreadsheet editors may expose identically named functions, but naming alone does not prove equivalent coercion, domain error codes, or release support. Formula portability must be tested in the actual target software and version. No such third-party result is used to establish ONLYOFFICE behaviour here.

• Documentation scope: The current ONLYOFFICE Help Center function reference lists LOG in the Math and Trigonometry catalogue and gives the syntax above. The page does not identify the first supported Desktop, Docs server or self-hosted release. The listing is evidence of present documentation, not an execution test across editions.
• Desktop/web: The separate Desktop Editors changelog and browser-oriented Spreadsheet Editor guide exist, but a specific minimum version for LOG was not established. Do not label all historical versions compatible.
• Locale: ONLYOFFICE advanced settings documents formula language and regional numeric formatting. The formulas here use English names and decimal-point notation. Localized formula names, separators and translated errors remain pending native verification.
• File exchange: These examples are designed around workbook formulas and simple numeric cells; saved-file round trips and cross-application differences were not executed.

Native Desktop/web execution, text/blank coercion, invalid-argument errors, regional formula entry, historical release support and workbook round trips remain unverified.