Percentage Change Calculator
Percentage Change Calculator
The percentage change calculator measures how much a value has increased or decreased relative to its original amount.
Conversion Formula
Percentage Change = ((New − Old) ÷ |Old|) × 100. A positive result indicates an increase; a negative result indicates a decrease.
Step-by-Step Examples
Old: 50, New: 75 = 50%
(75 − 50) ÷ 50 × 100 = 50% increase.
Old: 100, New: 80 = -20%
(80 − 100) ÷ 100 × 100 = -20% decrease.
Old: 200, New: 200 = 0%
No change between the values.
History
Percentage change calculations became fundamental in economics and business during the industrial revolution as tracking growth and decline became essential for decision-making.
Common Use Cases
- Tracking stock price movements
- Measuring sales growth
- Comparing year-over-year performance
- Calculating inflation rates
Frequently Asked Questions
How do I calculate percentage change?
Subtract the old value from the new value, divide by the absolute value of the old value, and multiply by 100.
What is the difference between percentage change and percentage difference?
Percentage change measures the shift from a specific starting value, while percentage difference compares two values without a defined starting point.
Can percentage change be negative?
Yes. A negative percentage change indicates a decrease from the old value to the new value.
What if the old value is zero?
Percentage change is undefined when the old value is zero because division by zero is not possible.
How do I interpret a 100% increase?
A 100% increase means the new value is exactly double the old value.
What is a percentage point vs percentage change?
A percentage point is the arithmetic difference between two percentages (e.g., 5% to 8% is 3 points), while percentage change is the relative difference.
How is percentage change used in finance?
It measures stock price movements, revenue growth, inflation rates, and investment returns over time.
Is percentage change the same as growth rate?
For a single period, yes. For multiple periods, growth rate typically refers to compound annual growth rate (CAGR).