The logarithm (log (x)) of a number is the power that a fixed value, called a base, must be raised to produce that number.

For example: *b ^{ y} = x*

Then : log* _{b }x* =

Some important rules of Logarithms:

- Rules of multiplication: log
_{a}xy = log_{a}x + log_{a}y - Quotient Rule : log
_{a}= log_{a}x – log_{a}y - Change Of Base Rule:
Logarithm power rule: log

(_{b}*x*) =^{y}*y ∙*log(_{b}*x*)

Logarithm Calculator is a tool that calculates the log value of any positive real number with a given base.

Using:

Enter the number and base of the logarithm (note: the base of the logarithm cannot be equal to 1).

Click Calculate to perform the calculation.