Percentage Change Calculator
Calculate the percentage increase or decrease between two values quickly and accurately.
What Is the Percentage Change Calculator?
The percentage change calculator determines the relative change between two values as a percentage. It tells you whether a value has increased or decreased and by how much, expressed as a percentage of the original value.
Formula
How to Use
Enter the original (old) value and the new value. Click Calculate. A positive result means an increase; a negative result means a decrease.
Example Calculation
If a product was $80 last month and is $100 this month: ((100 − 80) / 80) × 100 = 25% increase.
Understanding Percentage Change
Percentage change is one of the most common calculations in business, finance, and science. It answers the question: "By what percent did a value increase or decrease?"
Investors use it to track portfolio performance. Businesses use it to measure revenue growth. Scientists use it to compare experimental results. Students encounter it in math, economics, and data analysis courses.
A key advantage of expressing change as a percentage is standardization. Saying revenue grew by $10,000 means different things for a small business versus a corporation. But saying revenue grew by 15% is immediately meaningful regardless of scale.
Our calculator handles both positive and negative changes and shows the direction (increase or decrease) clearly. It uses the absolute value of the original number in the denominator to ensure correct results even when working with negative values.
Frequently Asked Questions
What is the difference between percentage change and percentage difference?
Percentage change measures the change relative to the original value. Percentage difference compares two values relative to their average. Change has a direction (increase or decrease); difference does not.
Can percentage change exceed 100%?
Yes. If a value doubles, that is a 100% increase. If it triples, it is a 200% increase.
What if the original value is negative?
The formula uses the absolute value of the original, so it works with negative numbers too.
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