Excel LOG function

Function              LOG

Description        Excel LOG function returns the logarithm of a given number with a given base.

Syntax  LOG( number, [base] )

number  The numerical value of which logarithm has to find out.

base      [optional]  this argument that specifies the base to which the logarithm should be calculated. By default it is 10 if omitted.

Example:

=LOG(100,10) = 2

=LOG(128,2) = 7