Returns the base10 logarithm of a number.
Syntax
LOG10(number)
Number is the positive real number for which you want the base10 logarithm.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

A 
B 
Formula 
Description (Result) 
=LOG10(86) 
Base10 logarithm of 86 (1.934498451) 
=LOG10(10) 
Base10 logarithm of 10 (1) 
=LOG10(1E5) 
Base10 logarithm of 1E5 (5) 
=LOG10(10^5) 
Base10 logarithm of 10^5 (5) 
