---
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
---

> ## 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)

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