Percentage Change Calculator
Measure how much a value changed from a starting number to a new number.
Percentage Change Calculator
Percentage Change Calculator Formula
Use this formula to check the result from the percentage change calculator or to calculate it by hand.
Formula
((new value - old value) / |old value|) x 100
Example
Steps
- 180 - 100 = -20
- 2-20 / 100 = -0.2
- 3-0.2 x 100 = -20%, or a 20% decrease
When to use this calculator
Worked examples
From 100 to 80 is a 20% decrease.
From 80 to 100 is a 25% increase.
Common mistakes
- Using percentage difference when you actually need old-to-new percentage change.
- Treating a negative result as an error instead of a decrease.
Other Calculators
Simple tools for nearby percentage questions.
Percentage Calculator
Calculate a percentage, percent of a number, or part of a whole.
Percentage Increase Calculator
Find percent growth from one value to another.
Percentage Difference Calculator
Compare two values using percentage difference.
Percentage Decrease Calculator
Find percent decrease from an original value to a lower value.
Discount Calculator
Find sale prices and savings from a discount percent.
FAQ
Yes. A negative result means the new value is lower than the old value.
No. Percentage change uses the old value as the reference. Percentage difference uses the average of both values.