LOG10 Function in Excel: Base-10 Logarithm

LOG10 Function in Excel: Base-10 Logarithm featured illustration

📎 This article includes 1 downloadable practice file ↓

⏱ 2 min readUpdated 5 October 2026

MathLevel: IntermediateAvailable in: Excel 2007+

In this article
  1. Syntax
  2. Examples
  3. Example 1
  4. LOG10 in practice
  5. Where you will use it
  6. Worked example
  7. Mistakes people make
  8. Related functions
  9. Continue learning

LOG10 tells you the order of magnitude. Charts of values ranging from hundreds to crores are easier to read on a log scale.

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Syntax

=LOG10(number)
Argument What it means
number Positive.

Examples

Example 1

=INT(LOG10(A2))

2 for 350, 5 for 2,40,000 — group customers by size band.

LOG10 in practice

Where you will use it

  • Decibels and pH
  • Number of digits: INT(LOG10(n))+1
  • Log scales for charts

Worked example

ValueFormulaResult
1000=LOG10(A2)3
1=LOG10(A3)0
5000000=LOG10(A4)6.698970004

Results calculated in Excel.

Mistakes people make

MistakeWhat to do instead
Zero or negative#NUM!
Natural logUse LN for base e

LOG · LN

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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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