LOG in Collabora Office: Choose a Logarithm Base and Check the Default
Use LOG in Collabora Office Calc with explicit bases, the default base ten, reciprocal bases and exponent-solving examples.
Verification status: See the evidence and test scope described in this guide. How formula examples are checked
Quick answer: LOG returns a logarithm using a selected base. =LOG(32;2) is expected to return 5, because two raised to the fifth power is 32. Omitting the base uses ten in the documented Collabora syntax.
Availability and version history
- Introduced: documented by Collabora Office 26.04; the original introduction release is not established.
- Availability:
LOGis documented in the official 26.04 Calc Help. - Scope: desktop Calc documentation; separately deployed Online and mobile versions have not been verified.
- Checked: October 13, 2026, against the official LOG reference. Documentation check; not a native application test. Expected examples are independently calculated.
Syntax and defaults
=LOG(number; [base])
The first argument is the value being expressed as a power. The second is optional; the official reference specifies a default of 10. Specify it explicitly when a workbook mixes several kinds of logarithms.
For real logarithms, use a positive input, a positive base and a base other than one. The examples deliberately stay inside this domain. The exact application error presentation for out-of-domain values has not been native-tested here.
A base below one is mathematically allowed, but it reverses the direction in which the logarithm changes. Do not assume every negative output signals an invalid argument.
Example 1: read logarithms as exponent questions
Enter this input table in A1:B4. The expected-result column is explanatory, not another input column.
| Number | Base | Expected result |
|---|---|---|
| 32 | 2 | 5 |
| 81 | 3 | 4 |
| 0.01 | 10 | -2 |
Put =LOG(A2;B2) in C2 and fill down through C4. Check each answer by raising the base to that exponent: 2^5=32, 3^4=81 and 10^-2=0.01.
The function returns the exponent. It does not return the base or the original number, even when one of those happens to be a familiar logarithm value.
Example 2: make the omitted-base behavior visible
=LOG(1000)
=LOG(1000;10)
Both are expected to return 3. The first expression uses the documented default base ten. This default differs from LN, which uses e.
When checking a transferred workbook, inspect omitted optional arguments rather than assuming another similarly named function uses the same default. An explicit base also makes formulas easier to interpret without consulting reference material.
Example 3: an admissible base below one
=LOG(8;0.5)
Expected result: -3. One half raised to the power −3 equals eight. A negative exponent is the correct solution, even though the input and base are both positive.
For a base greater than one, larger positive inputs have larger logarithms. For a base between zero and one, the relationship reverses. Select the base from the model, not merely to force the sign you expect.
Advanced example: solve a repeated-growth exponent
A hypothetical quantity begins at 200 and becomes 266.2 after repeated multiplication by 1.1. To solve for the number of periods:
=LOG(266.2/200;1.1)
Expected result: approximately 3. The ratio is 1.331, and 1.1^3 is 1.331. Floating-point representation can make a calculated result very close to three rather than an identical printed integer.
This assumes the same growth factor applies every period. Variable rates require a different model, and a real observation need not follow the hypothetical rule exactly. The formula solves the stated equation; it does not establish that the model fits reality.
Cross-check with natural logarithms
For the positive number 32 and base 2:
=LN(32)/LN(2)
Expected result: approximately 5. This is the change-of-base relationship. It supplies an independent structural check of what LOG means, although both calculations still use finite-precision arithmetic in a spreadsheet.
A denominator of LN(1) would be zero, explaining why base one is invalid. A positive base very close to one can make the result sensitive to small input differences. Check that the scale is meaningful before interpreting many output digits.
Troubleshooting and native verification
Verify argument order, positivity and the base. A result near 0.3 instead of 3 can indicate a different input magnitude; a result near 6.907755 for 1000 suggests that LN was used instead of a base-ten logarithm.
Keep decimals in the original data and round only the presentation unless the model expressly requires rounding. For a native acceptance test, record the build and compare the three-row table, omitted-base pair, reciprocal-base example and exponent solution. The guide provides independent expected arithmetic, not application execution evidence.
Official reference
- Collabora Office 26.04: LOG, checked October 13, 2026.
- Editorial standards.