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Last updated on June 10th, 2025

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Percentage Change

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The way of expressing a number or ratio as a fraction of 100 is the percentage. Percentage change is the change in the value, it can be the increase or decrease of the value. In real life, we use it to calculate the loss and profit, analyze population growth, salary increase, and so on.

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What is the Percentage Change

The amount of change in the final and initial value as a fraction of 100 is the percentage change. Percentage change is the difference between the new value and the old value divided by the old value multiplied by 100. 

That is percentage change =

 

The percentage change can both increase and decrease. The percentage increase is the change in percentage where the final value is greater than the initial value.
The percentage decrease is the change in percentage where the final value is lesser than the initial value.
 

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Methods to Calculate the Percentage Change

There are different methods to find the percentage change. Let’s learn a few methods to find the percentage change. 

 

Finding the Percentage Change Using Formula

To find the percentage change we use the formula 

Percentage change = 

 

For instance, the price of a jacket has increased from 50 to 65. What is the percentage increase?
 

To find the percentage increase we use the formula, 

 

Final value = 65
Initial value = 50
Percentage increase = 
 

=(15/50) × 100 = 30%

 

Using formula - for percentage increase:

To find the percentage increase the formula used is:
Percentage increase = 

 

Using formula - for percentage decrease:

To find the percentage decrease the formula used is:

Percentage decreased = 

 

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Tips and Tricks For Percentage Change


Tips and tricks are always interesting and easy to remember for students. Here are a few tips and tricks to learn and master percentage change. 

 

  • Memorizing the formula: The best way to calculate the percentage change is by memorizing the formula. That is percentage change = 
     
  • Identifying the initial and final value: When working on percentage change it's important to identify the initial and final value to get the accurate report.
     
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Common Mistakes and How to Avoid Them in Percentage Change

When calculating the percentage change students make few errors. In this section, we will learn a few common mistakes and ways to avoid them. 

Mistake 1

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Confusing with the formula 

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When calculating percentage change students wrongly understand the initial and final value. To avoid that error students need to identify the initial and final value. The formula to apply is percentage change 

Mistake 2

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Confusing with the base value

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When calculating the percentage change confusion with the base value is common among students. Using the final value instead of the initial value as the base is a common mistake. Students should remember that the base value is the initial value, not the final value.

Mistake 3

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Forgetting to multiply the result with 100

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Not multiplying the result with 100 will lead to the wrong answer. So students should not forget to multiply the decimal with 100 to get the correct answer.

Mistake 4

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Misidentifying the percentage change in word problems 

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When working on word problems students confuse with the increase and decrease of the percentage change. They should read the questions carefully to understand the increase and decrease in percentage. 
 

Mistake 5

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Not adding the percentage symbol % in the final answer
 

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When writing the final answer it is important to add the percentage symbol that is %.  It is significant to add the percentage symbol in the final answer.

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Percentage Change Examples

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Problem 1

A jacket was originally priced at $80, but the store increased the price to $100. What is the percentage increase?

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The percentage increase is 25%

Explanation

To find the percentage increase we use the formula, 


percentage change = 

Here, final value = 100

Initial value = 80

So, the percentage increased =                       = (20/80) × 100 = 25%
 

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Problem 2

A student scored 60 marks in a test. After studying harder they scored 75 marks in the next test. What was the percentage increase?

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The percentage increase is 25%

Explanation

 To find the percentage increased we use the formula,


percentage change =

Here, initial value = 60

Final value = 75

That is percentage change =                 = = (15/60) × 100 = 25%
 

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Problem 3

A car was worth $20,000 last year, but its value dropped to $15,000. What is the percentage decrease?

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 The percentage decrease is 25%
 

Explanation

We use the formula, percentage change =

Here, the old value = 20000

New value = 15000

percentage change =                   = (5000/20000) × 100 = 25%
 

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Problem 4

A laptop was originally $1,200, but it is now on sale for $900. What is the percentage decrease?

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The percentage decrease = 25%
 

Explanation

We use the formula, percentage change = 

Here, the old value = 1200

New value = 900


percentage change =                     = (300/1200) × 100 = 25%

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Problem 5

A tenant’s rent increased from $800 per month to $880 per month. What is the percentage increase?

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 The percentage increase is 10%
 

Explanation

We use the formula, percentage change = 


Here, the old value = 800

New value = 880

percentage change =               = (80/800) × 100 = 10%
 

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FAQs on Percentage Change

1.What is the percentage change?

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2.How do you calculate percentage change?

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3.Where is percentage change used in real life?

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4.Is the percentage change always positive?

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5.Does percentage change work the same for large and small numbers?

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6.What is the percentage change from 80 to 120?

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Dr. Sarita Ghanshyam Tiwari

About the Author

Dr. Sarita Tiwari is a passionate educator specializing in Commercial Math, Vedic Math, and Abacus, with a mission to make numbers magical for young learners. With 8+ years of teaching experience and a Ph.D. in Business Economics, she blends academic rigo

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