LOG

The LOG function returns the natural logarithm of a number.

LOG( number )

The number argument can be any valid numeric expression that results in a value greater than 0. The natural logarithm is the logarithm to the base e. The constant e is approximately 2.718282. You can calculate base-n logarithms for any number x by dividing the natural logarithm of x by the natural logarithm of n as follows:

LOGN( x ) = LOG( x ) / LOG( n )