Enter any number into the calculator below to determine the log base 2 of that number. To calculate the log of that number in any other base, simply enter that into the calculator below.

## Log Base 2 Formula

The following formula is used by the calculator above to calculate the log of a number.

## Log Base 2 Definition

Conceptually, the log of a number y with base b is equal to the exponential value the base needs to be raised to in order to equal y. In other words, if you have a problem, say log base 2 of 4, the answer is 2 because 2^2=4.

## Log Example

Let’s take a look at a step-by-step example of how to calculate the log of a number with any base.

- First, the number that we are to take the log of must be determined, For this example we will say that number, y, is equal to 25.
- Next, the base of the log needs to be chosen. For this example, we will take a base of 5.
- Finally, we need to set up the equation above to solve for X. So the log base 5 of 25.
- The answer to this equation is 2 since 5^2=25. 2 is the number that 5 needs to be raised to in order to equal 25.