Log Function

This page is specific to the Visual Basic for Applications (VBA) Language Reference for Office 2010.

Returns a Double specifying the natural logarithm of a number.

Syntax

Log(number)

The required number argument is a Double or any valid numeric expression greater than zero.

Remarks

The natural logarithm is the logarithm to the base e. The constante 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)

The following example illustrates a custom Function that calculates base-10 logarithms:

Static Function Log10(X)
    Log10 = Log(X) / Log(10#)
End Function

Example

This example uses the Log function to return the natural logarithm of a number.

Dim MyAngle, MyLog
' Define angle in radians.
MyAngle = 1.3
' Calculate inverse hyperbolic sine.
MyLog = Log(MyAngle + Sqr(MyAngle * MyAngle + 1))