Use our Percentage Change Calculator at for quick and precise calculations of percentage increases or decreases. Ideal for homework, financial management, or numerical analysis, this tool ensures accuracy and ease in every use.

How to Use Percentage Change Calculator

Step 1: Identify Your Numbers

Determine the original value (“old number”) and the new value (“new number”) for which you need to calculate the percentage change.

Step 2: Input the Values

Enter the old number in the first input box labeled ‘Start Value’ and the new number in the second input box labeled ‘End Value’.

Step 3: Review the Result

As you input the values, the calculator automatically applies the formula:
Percentage Change=(Start ValueEnd Value−Start Value​)×100
The percentage change will immediately display in the output field, indicating the increase or decrease from the old number to the new number as a percentage.

Step 4: Clear and Repeat

If you need to perform another calculation, click the ‘Clear’ button to reset all fields and input new values as needed.

How to Calculate Percentage Change

Calculating the percentage change between two values helps you determine how much a quantity has increased or decreased over time. Here’s a step-by-step guide on how to calculate percentage change:

Step 1: Identify the Initial and Final Values

First, determine the starting value (Initial Value) and the ending value (Final Value) for which you want to calculate the change.

Step 2: Calculate the Difference

Subtract the Initial Value from the Final Value to find the difference. This tells you the absolute change between the two values.

Difference=Final Value−Initial Value

Step 3: Divide the Difference by the Initial Value

Take the result from Step 2 and divide it by the Initial Value. This ratio gives you the change relative to the starting point.

Relative Change=Difference/Initial Value

Step 4: Convert to Percentage

To convert the relative change into a percentage, multiply the result from Step 3 by 100.

Percentage Change=(Relative Change)×100%

Step 5: Interpret the Result

The final result is your percentage change. A positive value indicates an increase, while a negative value indicates a decrease.

Percentage Change Formula

The percentage change formula is a mathematical calculation used to determine the degree of change over time, expressed as a percentage. This formula helps in understanding how much a quantity has increased or decreased in comparison to its original value.


Percentage Change=(Final Value−Initial Value/Initial Value)×100

Examples of Percentage Change Calculator

Example 1: Increase in Rent

  • Initial Rent: $1,000 per month
  • Final Rent: $1,200 per month
  • Calculation:Percentage Change=(1200−1000/1000)×100=20%
  • Result: The rent increased by 20%.

Example 2: Decrease in Stock Value

  • Initial Stock Price: $150
  • Final Stock Price: $120
  • Calculation:Percentage Change=(120−150/150)×100=−20%
  • Result: The stock value decreased by 20%.

Example 3: Increase in Population

  • Initial Population: 50,000
  • Final Population: 55,000
  • Calculation:Percentage Change=(55000−50000/50000)×100=10%)×100=10%
  • Result: The population increased by 10%.

Example 4: Decrease in Sales

  • Initial Sales: $20,000
  • Final Sales: $18,000
  • Calculation:Percentage Change=(18000−20000/20000)×100=−10%
  • Result: Sales decreased by 10%.

Example 5: Increase in Website Traffic

  • Initial Traffic: 8,000 visitors per month
  • Final Traffic: 10,000 visitors per month
  • Calculation:Percentage Change=(10000−8000/8000)×100=25%
  • Result: Website traffic increased by 25%.

What is a percentage change calculator used for?

A percentage change calculator is used to determine the percentage increase or decrease from one value to another over time, helping users understand growth or decline in values such as prices, quantities, or measurements.

How accurate is a percentage change calculation?

The accuracy of a percentage change calculation depends on the precision of the input values. Accurate inputs yield accurate percentage changes.

Can I use percentage change to compare data from different scales?

Yes, percentage change normalizes differences by comparing changes relative to the initial values, making it possible to compare data from different scales effectively.

How do fluctuations in data affect percentage change calculations?

Fluctuations can lead to large percentage changes especially when the initial value is small. It’s important to consider the context of the data and whether temporary fluctuations or outliers might skew the percentage change.

How do I use a percentage change calculator for financial analysis?

In financial analysis, a percentage change calculator can be used to evaluate the performance of investments by comparing the percentage change in investment value over time.