To specify the base for Math.log(), change the base by dividing by log(10).
Example
You can try to run the following code to implement adding a base for Math.log() −
<html> <head> <title>JavaScript Math log() Method</title> </head> <body> <script> var value = Math.log(100)/Math.LN10; document.write("Value : " + value ); </script> </body> </html>