The percentage change calculator is a valuable tool for various fields such as finance, chemistry, and mathematics, providing insights into changes between two values. Understanding the percent change formula is crucial for accurate calculations. The percent change differs from percent increase and percent decrease, capturing both directions of change. It is applicable in scenarios like population growth rate calculations and expressing relative errors.

## Calculating Percentage Change:

To calculate percentage change:

1. Find the difference between the initial and final values.
2. Divide by the absolute value of the initial value.
3. Multiply the result by 100.

Formula: Percent Change=100×(Final−Initial∣Initial∣)Percent Change=100×(∣Initial∣Final−Initial​)

Ensure the correct handling of negative values to avoid errors.

### Examples:

Example 1: Given values 60 (initial) and 72 (final): Percent Change=72−60∣60∣×100=20%Percent Change=∣60∣72−60​×100=20%

Example 2: Values 50 (initial) and -22 (final): Percent Change=−22−50∣50∣×100=−144%Percent Change=∣50∣−22−50​×100=−144%

## Handling Negative Numbers:

When dealing with negative numbers: Percent Change=New−Old∣Old∣×100Percent Change=∣Old∣New−Old​×100

Example: Calculate percentage change from -20 to -30: Percent Change=−30−(−20)∣−20∣×100=−50%Percent Change=∣−20∣−30−(−20)​×100=−50%

## Population Growth Rate Formula:

Population growth rate measures changes in population over time:

Population Growth Rate=Population GrowthPrevious Population×100Population Growth Rate=Previous PopulationPopulation Growth​×100

Example: In the U.S., population grew from 253,339,000 in 1990 to 310,384,000 in 2010: Population Growth Rate=310,384,000−253,339,000253,339,000×100=22.5%Population Growth Rate=253,339,000310,384,000−253,339,000​×100=22.5%

The percentage change calculator is not only valuable in academic settings but also practical in everyday situations, such as assessing sales tax or negotiating salaries. Understanding how to calculate percent change manually ensures real-world applicability.

## FAQs:

1. Is percentage difference equal to percentage change?
• No, they are distinct. Percentage change can be positive or negative, while percentage difference is always positive.
2. What is the percentage change from 5 to 20?
• 20 is a 300% increase of 5.
3. What is the percentage change from 20 to 10?
• 10 is a 50% decrease of 20.
4. What is the percentage change from 2 to 3?
• 3 is a 50% increase of 2.
5. What is the percentage change from 5 to 4?
• 4 is a 20% decrease of 5.