How to Calculate Percentage

How to calculate percentages? A brief guide of Percentage formulas with example and Solution steps.

Knowing how to calculate and use percentage helps you not only in scoring Math’s but also in real-life problems like you can calculate tips in restaurants or statistics of your favorite outdoor games.

The calculating percentage is actually quite easy. Just use the percentage formula to find out percentage and any unknown to a particular equation.

How to calculate percentages?

There are many formulas of finding percentages depending upon user requirements. The basic one is

x/y = p * 100 where x and y are numbers and p is a percentage.

Below are the Mathematical percentage formulas:

  1. Find the percentage of a number x? --------------------Formula # 1: p% * x = y

  2. What percentage of number x is number y? -----------Formula # 2: y/x = p%

  3. Find number x if the percentage of it is number y?----Formula # 3 : y/(p%) = x

1. Find the percentage of a number x? --------- Formula # 1: p% * x = y

Let’s take an example:


Q#1: What is the 70 % of 150?

  • If p = 70% and x = 150 ------------than convert into an equation like formula above
  • 70% * 150 = y
  • 70/100 * 150 = y---------------------convert percentage into 100 as 1 % = 1/100
  • 105 = y---------------------------------by reducing it.
  • You can say that 70% of 150 is 105.

2.What percentage of number x is number y? --------- Formula # 2: y/x = p%

Let’s take an example:


Q#1:What percentage of 90 is 20?

  • If x= 90 and y = 20--------------------than convert into an equation like formula above
  • 20/90 = p %
  • 0.22= p %--------------------------------put result in percentage form.
  • 0.22 * 100 = 22.2 % -------------------- is percentage of p
  • You can say that 22.2 % is percentage of 90 is 20.

3. Find number x if the percentage of tis number y? --------- Formula # 3: y/(p%) = x

Let’s take an example:


Q#1: 50 is 25% of what number?
* If y= 50 and p%= 25%----------------than convert into an equation like formula above

  • 50/(25%) = x ---------------------------solve the 25% = 25/100 = 0.25 and put in formula.
  • 50/0.25 = x
  • 200 = x you can say that 50 is 25% of number 200.
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