--- title: "Use the LN Function to Calculate Natural Logarithms of Numbers" slug: "ln-function" description: "Learn to use the LN function to return the natural logarithm of a number using base e—essential for financial and statistical modeling." updated: 2025-05-30T09:40:42Z published: 2025-08-22T10:57:28Z canonical: "kb.pigment.com/ln-function" --- > ## Documentation Index > Fetch the complete documentation index at: https://kb.pigment.com/llms.txt > Use this file to discover all available pages before exploring further. # LN function ## Description Returns the natural logarithm of a number. The natural logarithm uses the mathematical constant e (roughly equal to 2.71828) as base. It is the opposite of the `EXP` function. ## Syntax `LN(Number)` ## Arguments | Argument | Type | Dimensions | Description | | --- | --- | --- | --- | | *Number* (required) | Number | Any Dimensions | Number to return the natural logarithm for. | ## Returns | Type | Dimensions | | --- | --- | | Number | Dimensions of *Number* | `LN(0)` returns `BLANK`. Negative *Numbers* return `BLANK`. ## Examples | Formula | Result | Description | | --- | --- | --- | | `LN(1)` | 0 | ln(1) equals 0. | | `LN(45)` | 3.80666... | ln(45) roughly equals 3.80666. | | `LN(0.2)` | -1.60943 | ln(0.2) roughly equals -1.60943. | | `LN(-2)` | `BLANK` | -2 is a negative number, the function returns `BLANK`. | | `LN(EXP(2))` | 2 | As `LN` and `EXP` perform inverse operations, the output is the same as the input. | ## See also Excel: [LN](https://support.microsoft.com/en-us/office/ln-function-81fe1ed7-dac9-4acd-ba1d-07a142c6118f) Related articles: [LOG](/v1/docs/log-function), [EXP](/v1/docs/exp-function)