The Excel LOG function is a Math formula that returns the logarithm of a given number and base. In this guide, we’re going to show you how to use the LOG function and also go over some tips and error handling methods.
Supported versions
- All Excel versions
Excel LOG Function Syntax
Arguments
number |
A positive real number for which you want the logarithm. |
[base] |
Optional. The base of the logarithm. The default value is 10. |
Examples
With [base]
Use the LOG function to calculate the logarithm of the argument number to the base 10. The equivalent math formula for this example would be log_{10}number. Based on this, we can say that =LOG(number, 10) equals LOG(number). Here is a sample use:
Without [base]
Enter a value for the argument [base] to calculate the logarithm of the number to the specified base. For example,
Tips
- The equivalent math formula for this function is =log_{[base]}number
- When the [base] argument is omitted, Excel will calculate logarithm of number to base 10 by default.
- You can also use LOG10 function for base 10.
- Use the LN function to calculate the natural logarithm of a given number.
Issues
The number argument should be a positive real number. Zero (0) or negative numbers will return a #NUM! error.