LOG10 in Collabora Office: Base-Ten Logarithms and Orders of Magnitude

• Introduced: documented by Collabora Office 26.04; the original introduction release is not established.
• Availability: LOG10 is 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 LOG10 reference. Documentation check; not a native application test. Expected examples are independently calculated.

=LOG10(number)

The argument is the positive value whose base-ten logarithm is required. A zero or negative value has no finite real logarithm for this operation. Correct the data or choose an appropriate mathematical model rather than silently replacing a domain failure with zero.

Collabora’s official reference identifies the base as ten. LOG can express the same operation with an explicit base of ten, while LN uses e. These operations share a general idea but do not return interchangeable numerical values.

Enter the following numeric inputs in A2:A6 and put =LOG10(A2) in B2, filling down.

An input between zero and one gives a negative logarithm. This is valid and distinct from an invalid negative input. One gives zero because the zero power of ten is one.

For small values, verify that the source cell is numeric and has not been rounded to a stored zero during import. A display format that merely hides small decimals is a separate issue.

=LOG10(25)

Expected result: approximately 1.397940 to six decimal places. Twenty-five lies between 10 and 100, so its logarithm lies between 1 and 2. That interval check can reveal a misplaced decimal even before a calculator is used.

Compare the result with =10^LOG10(25), which is expected to recover approximately 25. Use a reasonable numerical tolerance after a chain of calculated operations rather than demanding a particular last binary digit.

Put 1000 in D2 as a reference quantity and 1000000 in E2 as the comparison quantity, both measured in the same unit.

=LOG10(E2/D2)

Expected result: 3. The ratio is 1000, so the second quantity is three powers of ten larger than the reference.

This statement concerns the ratio. It is not a difference of three original units. A thousand-fold increase is also not a 1000% increase; logarithmic, ratio and percentage descriptions must be labeled according to their definitions.

Suppose a display covers positive values from 10 through 10000, and you want a normalized position for the value 100:

=(LOG10(100)-LOG10(10))/(LOG10(10000)-LOG10(10))

Expected result: 1/3, approximately 0.333333. The lower and upper logarithms are 1 and 4. The test value’s logarithm is 2, placing it one third of the way across that log interval.

The same expression gives 0 for value 10 and 1 for value 10000. It gives values outside 0–1 for positive inputs outside the chosen bounds. Clamp only if the display specification requires it; clamping changes the represented information.

=LOG10(20*50)
=LOG10(20)+LOG10(50)

Both are expected to return approximately 3. The product is 1000. Adding logarithms corresponds to multiplication of positive source quantities, not addition of those quantities.

In contrast, LOG10(20+50) is the logarithm of 70 and is not three. Parentheses and the operation inside them are part of the mathematical question.

A log scale can make multiplicative differences easier to compare, but it changes visual spacing. Equal steps on the log scale represent equal ratios, not equal additions in the original measurement.

Check domain, units, input magnitude and base before changing a formula. Very small positive values may face representation limits; this article does not specify a universal underflow threshold for every Collabora version.

For native validation, record the build and compare the five powers of ten, 25, the ratio and the normalized position. All expected values are independently calculated. No Collabora application execution or screenshot is claimed.

• Collabora Office 26.04: LOG10, checked October 13, 2026.
• Editorial standards.