What Is a Percentage Change Calculator?
A percentage change calculator determines the relative difference between two values, expressed as a percentage. It computes both percentage increase and decrease, making it essential for analyzing financial returns, price changes, population growth, and performance metrics across any domain that tracks change over time.
How to Use This Percentage Change Calculator
- Enter the original (old) value in the first field.
- Enter the new value in the second field.
- Click Calculate to see the percentage change, absolute difference, and whether it is an increase or decrease.
Key Concepts
Percentage change = ((New Value − Old Value) ⁄ |Old Value|) × 100%. A positive result indicates an increase and a negative result indicates a decrease. For example, a price rising from $50 to $65 is a 30% increase: ((65 − 50) ⁄ 50) × 100% = 30%. Note that percentage changes are not symmetric: a 50% increase followed by a 50% decrease does not return to the original value (e.g., 100 → 150 → 75).
Change % = ((New − Old) ÷ |Old|) × 100
Frequently Asked Questions
What is the difference between percentage change and percentage difference?
Percentage change measures the relative shift from an original value to a new value and has direction (increase or decrease). Percentage difference compares two values without designating one as the baseline, using their average as the denominator.
Why does the order of values matter?
The order matters because the old value serves as the denominator. Changing from 200 to 300 is a 50% increase, but changing from 300 to 200 is a 33.3% decrease. The reference point determines the percentage.
Can percentage change exceed 100%?
Yes. If a value doubles, the percentage change is 100%. If it triples, it is 200%. There is no upper limit. A stock rising from $10 to $50 represents a 400% increase.