This calculator can compute logs for any number base.

To Find A Logarithm

1) Click on the logarithm button.
2) Enter the number to the right of the “Logarithm of” box.
3) Select the number base. You have 4 choices: base ‘e’, base ’10’, base ‘2’ and “Other”. If you don’t choose any base, the default is base 10. To use the ‘Other’ option, click that button and then enter the number base you want. (Remember to click that button. Just entering a number is not enough).
4) Click ‘ENTER’ and you will have your answer.

EXAMPLE: the base 17 logarithm of 23 is 1.1066918849.
Enter this by clicking logarithm, entering 23 in the logarithm input box, clicking “other” for the number base, entering 17 then clicking “ENTER” and your answer should be 1.1066918849.

To Find An Anti-Logarithm

EXAMPLE: The base 6 anti-log of 3.4 is 442.29726239.
1) Click the anti-log button

2) Enter 3.4 in the ‘Anti-Log of’ box

3) Click ‘Other’ for the number base and enter 6 in the input box

4) Click “ENTER: and your answer should be 442.29726239.

As you probably know, this is the same as saying 6^3.4 = 442.29726239.