LN Function in Excel: Natural Logarithm

LN Function in Excel: Natural Logarithm featured illustration

📎 This article includes 1 downloadable practice file ↓

⏱ 2 min readUpdated 5 October 2026

MathLevel: ExpertAvailable in: Excel 2007+

In this article
  1. Syntax
  2. Examples
  3. Example 1
  4. LN in practice
  5. Where you will use it
  6. Worked example
  7. Mistakes people make
  8. Related functions
  9. Continue learning

LN is the logarithm with base e. Finance uses it for continuously compounded (log) returns.

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Syntax

=LN(number)
Argument What it means
number Positive.

Examples

Example 1

=LN(C3/C2)

Daily log return of a price series.

LN in practice

Where you will use it

  • Continuous growth rates
  • Log returns of shares
  • Undo EXP

Worked example

ValueFormulaResult
1=ROUND(LN(A2),4)0
2.718281828=ROUND(LN(A3),4)1
100=ROUND(LN(A4),4)4.6052

Results calculated in Excel.

Mistakes people make

MistakeWhat to do instead
Zero or negative#NUM!
Base 10Use LOG10

EXP · LOG

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📎 Practice files for this article

  • 📗
    Practice workbook: Math & rounding24 tasks on realistic sales data — type your formula, the Check column turns green when it is right. Answers sheet included.
    ⬇ XLSX · 35 KB

Free to use for learning. Files with macros (.bas) are plain text — import them with Alt+F11 → File → Import File, and always test on a copy.

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