LN in Collabora Office: Natural Logarithms and Exponential Models

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

=LN(number)

The real logarithm is defined for positive input values. Use positive numbers in these examples. A zero or negative argument does not have a finite real natural logarithm; investigate such inputs rather than replacing a failure with an arbitrary zero. This guide does not claim a native-tested error code.

LN asks which exponent of e produces the input. It is different from the base-10 logarithm and from multiplying the input by e. The logarithm of one is zero, because e raised to the zero power equals one.

Enter 1, 2, 10 and 0.5 in A2:A5. Put =LN(A2) in B2 and fill down.

The negative output for 0.5 is valid: an input between zero and one has a negative logarithm. A negative logarithm is not the same as taking the logarithm of a negative input.

Use number formatting to display six decimals, but retain the underlying calculated value for subsequent operations. A displayed zero can hide a small nonzero result near one.

=LN(EXP(2))
=EXP(LN(7))

Expected results: approximately 2 and 7. The two functions reverse one another on this positive real domain. Compare with a sensible numerical tolerance rather than demanding identical long decimal strings after several calculations.

These identities do not guarantee that extreme exponents remain representable in a finite-precision spreadsheet. The small examples avoid overflow and underflow; they do not establish universal limits for every build.

Put an initial quantity of 80 in D2 and a later quantity of 100 in E2:

=LN(E2/D2)

Expected result: approximately 0.223144. The ratio is 1.25. The expression describes a logarithmic change, not a 22.3144% ordinary increase. The ordinary relative change is 100/80−1, or 25%.

Logarithmic and ordinary changes use different definitions. Label the result clearly so that readers do not confuse a log value with a conventional percentage change.

Suppose a modeled quantity follows final = initial*EXP(rate*time), with an initial value of 80, target 100 and a constant rate parameter 0.05 per period.

=LN(100/80)/0.05

Expected result: approximately 4.462871 periods. Taking LN of the ratio isolates rate×time; dividing by the rate gives the duration.

This is a hypothetical mathematical model, not a forecast or a guarantee. It assumes positive quantities, a nonzero rate, matching time units and a constant exponential rule. A target inconsistent with the direction of change can produce a negative duration, signaling that the model or question needs interpretation.

For positive inputs 4 and 5:

=LN(4*5)
=LN(4)+LN(5)

Both are expected to be approximately 2.995732. This identity is about multiplication. LN(4+5) is not equal to LN(4)+LN(5); the sum inside the logarithm cannot be split in that way.

Likewise, using raw dimensional quantities in a model deserves care. A ratio of quantities in the same units is dimensionless, while mixing incompatible units changes the number supplied to LN.

Check positivity, stored numeric types and the base your problem requires. If a logarithmic result has the wrong sign, inspect whether the ratio was reversed. If a solved duration is off by a large factor, check whether 5% was entered as 0.05 or incorrectly as 5.

Native verification should record the Collabora version and reproduce the four input values, both inverse checks and the duration example. All results here were independently calculated; none is claimed as a target-application observation.

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