How To Calculate Percentages

We will show you how to easily calculate a number of different percentages.


Calculating percentages can be a confusing task, but do not worry, the math is actually quite simple. If you are not interested in the maths but just want to work them out quickly, then why not check out our simple to use percentage calculators by Clicking Here.

What is X percent of Y?

First let's look at what is one of the most commonly asked percentage questions, what is X% of Y? For example, what is 20% of 300?

For the example above, lets refer to the first value (20)% as X and our second value (300) as Y, with these in mind you can apply the following sum to calculate the result.

( Y / 100 ) * X = ?

So first we divide 300 by 100, which gives us 3, which we then multiply by 20 to get 60

( 300 / 100 ) * 20 = 60

X is what percent of Y?

Next up let us take a look as to how we can calculate what percentage one number is of another, or in other words, X is what percentage of Y?

In this example lets calculate what percentage 50 is of 400. The math you need for this calculation is as follows.

X * ( 100 / Y ) = ?%

So first we need to divide 100 by 400, then we need to multiply that number by 50, which gives us a final result of 12.5%

50 * ( 100 / 400 ) = 12.5%

How To Calculate Percentage Increases / Decreases

Finally lets take a look as to how we can calculate the percentage increase or decrease between two numbers, X and Y.

The math required for this calculation looks a little like this:

( Y - X ) x ( 100 / X ) = ?%

For the purposes of this example, we will calculate the percentage difference from 90 to 125.

First we need to take away 90 from 125, and then multiply this by 100 divided by 90 giving us a percentage increase of 38.89% as shown below:

( 125 - 90 ) x ( 100 / 90 ) = 38.89%