What Is Percentage Change?
Percentage change describes by how much percent a value has changed compared to a starting value. It is one of the most important tools in business, science, and everyday life.
The Formula
Percentage Change = ((New Value - Old Value) / |Old Value|) x 100
A positive result means an increase, a negative result means a decrease.
Example 1: A stock rises from 80 to 100 EUR. Change = ((100 - 80) / 80) x 100 = +25%.
Example 2: Gas price drops from 1.80 to 1.62 EUR. Change = ((1.62 - 1.80) / 1.80) x 100 = -10%.
The Asymmetry of Percentage Change
An important pitfall: Percentage changes are not symmetric.
If a stock rises by 50% (from 100 to 150 EUR) and then falls by 50%, it doesn't return to 100 but ends up at 75 EUR (150 x 0.50 = 75).
To get from 150 back to 100, you would need a decline of only 33.3% (not 50%). This asymmetry is particularly relevant for stock prices and inflation rates.
Percentage Change vs. Percentage Points
When the unemployment rate rises from 5% to 6%, that's:
1 percentage point absolute increase, but +20% relative change ((6-5)/5 x 100 = 20%).
In reporting, these terms are frequently confused, which can lead to significant misunderstandings.
Applications of Percentage Change
**Salary negotiation:** 'I want 5% more' means an increase of EUR 150 on EUR 3,000, bringing it to EUR 3,150.
**Revenue development:** A revenue growth of 12% from EUR 500,000 to EUR 560,000.
**Price comparisons:** If gas rises from 1.50 to 1.80 EUR (+20%) and then drops to 1.60 EUR, the decrease is only -11.1%.
Use the 'Change' tab in our percentage calculator to instantly calculate the percentage change between any two values.