Reverse Percentage Calculator

Enter a number and the percentage of a number and this reverse percentage calculator will determine the original number. For example 25% of X is 5. Solving for X we find the the answer to be 4.

Reverse Percentage Formula

Percentages are numbers that are expressed as fractions. They are denoted by the symbol %. These numbers have no units and are there for dimensionless. For example, the percentage 25% is equal to a fraction of 1/4 and can be written as .25.

How to calculate reverse percentage?

Below are two different examples of how to calculate numbers from percentages, or otherwise known as reverse percentage.

  1. Let’s assume we a have a number 100. We find that this number is 25% of some original number. To determine the orginal number, we simply need to multiply 100 by the inverse of the equal fraction to 25%. So, 25%= 1/4 and the inverse of 1/4 = 4. Therefore the original number can be calculate as 100*4=400.
  2. In this example we are going to use a more abstract number and percent. Say we have a number that is some percent of another number. We will assume our number is 121 and that is 32% of another number X. To calculate x we must use the same process as the previous example. 121 * 100/32 (the inverse of .32). = 378.125.


What is a reverse percentage?

A reverse percentage is a method of determining an original number from the percentage and new number.

reverse percentage calculator