# Microsoft KB Archive/50453

Excel: Calculating the Inverse of a Logarithm PSS ID Number: Q50453 Article last modified on 02-26-1992 PSS database name: M_eXceL

1.x 2.20 3.00 | 2.x 3.00 | 2.20 2.21 3.00

MACINTOSH | WINDOWS | OS/2

Summary:

In Microsoft Excel, the logarithm of a number can be calculated with the following formula:

=LOG(X,n)

where “n” is the base, “X” is the initial value.

Thus, to calculate the inverse logarithm of a number, simply raise the base to the power of the value returned by the LOG function, as follows

=n^Y

where “Y” is the logarithm of the number.

For example, the logarithm of 100 with the base of 10 gives the result of 2:

LOG(100,10)=2

Thus, the inverse logarithm of 2 in the above example is as follows:

10^2=100

More Information:

There are two additional forms of LOG in Excel. LOG10 uses base 10 and is equivalent to using LOG(X,10). LN is the “natural log,” which uses base 2 and is equivalent to using LOG(X,2).

Additional reference words: 2.20 2.2 2.21 3.0 3.00 antilog

Copyright Microsoft Corporation 1992.