Returns the logarithm to the base N of a number.
LOGN(Number, N)
Number 
is the positive real number for which you want the logarithm to the base
N.
N  is the base.
Formula 
Description 
Answer 
=LN(86)  Natural logarithm of 86  4.454347 
=LN(2.7182818)  Natural logarithm of the value of the constant  1 
=LN(EXP(3))  Natural logarithm of e raised to the power of 3  3
