Percentage Formulas | How to Calculate Percentages of a Number?

Understanding percentage formula and its basic concept will help you in determining the cost of a product and many other things too. Here, we will learn what is the percentage, about basic percentage formulas, and why they are needed for students.

What is Percentages?

The term percentage is an English that literally means per hundred. This is the way of expressing a number as the part of a whole. Percent can also be written as either Fraction or decimal. For converting a percent to a fraction, you just have to divide it by hundred.

What is Percentages?

How to Calculate Percentages?

Calculating the percentage of a number is easy. You can start by writing the number that you want to convert into a percentage over the whole value and you will be given final output in the end. If you wanted to turn the fraction into a decimal by dividing the top number with the bottom number. In the last step, you just need to multiply the decimal with hundred to calculate the percentage.
Percentage Formulas

Basic Percentage Formulas

The percentage is easy to calculate if the total number of values is 100 but this is not possible all the item, so you need a formula where you can put the values and calculate the final outcome. With a complete list of basic percentage formulas, you can calculate the increase in percent, decrease in percent and many more concepts too. The basic percentage formula is shown below in the diagram –

\[\large Percentage = \frac{Value}{Total\:Value}\times 100\]

Find Percentage of a Number

To find the percentage of a number, you should look at the whole equal to 100 percent. Take an example, if you had 10 strawberries and you ate 2 then you have consumed 20 percent of strawberries out of all and left with 80 percent of the things.

  • Part/whole * 100% = final outcome
  • 2/10*100% = 20%
  • Remaining items = (100%-20% = 80%)

Percentage Problem with Solution

The word percentage is derived from a Latin word whose meaning is ‘by the hundred’. Here, Percentage tell you the number of parts out of 100. For example, if I had a bag full of 100 different type fruits and I said that 30 percent were Mango then you would get an exact idea that the number of mangoes in the bag was 30. Similarly, if the cost of the shirt is $100 and there is a 40 percent off on that particular shirt then you would know the exact price of shirt i.e. $60 ($100-$40 = $60).

Question 1: There are 200 students in a class. Out of them 85 are Boys. Find the percentage of Boys in the class?


Total Students in the Class = 200

Boys in the Class = 85

\[\large Percentage = \frac{Value}{Total\:Value}\times 100\]

\[\large % of Boys in the Class = \frac{85}{200}\times 100\]

% of Boys in the Class = (85/200)X100

= 85X100/200 = 85/2 = 42.5%

Percentage of Boys in the Class = 42.5%

Question 2: __% of 45 is 9


Total Value is 45and Value is 9

\[\large Percentage = \frac{Value}{Total\:Value}\times 100\]

= 9X100/45 = 100/5 = 20%

Questions 3: 47% of the students in a class of 34 students has glasses or contacts. How many students in the class have either glasses or contacts?

Percentage = 47%

Total Student = 34

Rest Student = ?

Suppose Rest Student = A

Percentage = Ax100/34

47 = A X 100/34

47 X 34/100 = A

A = 15.98 = 16

16 of the students wear either glasses or contacts.

Why Need Percentage Formula for Students?

The use of percentage is common in reference to the sports statistics like calculating the winning percentage of a team etc, the fraction of matches won by a team or more. Further, the percentage can also be used to calculate steepness of a curve in case of railways, or roads etc. It has various real-life applications and extremely important to learn by students to understand daily basics things happening around us.

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