Related Function:

The LN function returns the natural logarithm of a number. Natural logarithms are based on the constant e (2.71828182845904).

Syntax

=LN(number)

Arguments

Argument Description
number The positive real number for which you want the natural logarithm

Examples

  A B C
1 Formula Result Notes
2 =LN(76) 4.330733 Natural logarithm of 76
3 =LN(2.7182818) 1 Natural logarithm of the value of the constant e
4 =LN(EXP(4)) 4 Natural logarithm of e raised to the power of 4

Note: LN is the inverse of the EXP function.

Common Function Error(s)

Problem What went wrong
#NUM! Occurs if the supplied number argument is negative or zero
#NAME? Occurs if the supplied number argument is not a numeric value

The logarithm of a number, to a given base, is the power to which the base must be raised to give that number; it is the inverse operation to exponentiation.

The natural logarithm of a number, written ln\ x or log_e(x), is the logarithm to the base e.

Therefore,

    \begin{align*}\text{if}\   e^x &=y \\\text{then}\   ln(y) &= x \end{align*}

See Wikipedia for more information on Natural Logarithm.