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 formula

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.

  1. 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.
  2. Next, the base of the log needs to be chosen. For this example, we will take a base of 5.
  3. Finally, we need to set up the equation above to solve for X. So the log base 5 of 25.
  4. 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.
log base 2 calculator