What is Percentage Change?
Percentage change measures how much a value has increased or decreased relative to its original amount. It's expressed as a percentage and helps compare changes across different scales.
This is commonly used in finance, business, science, and everyday life to track growth, compare prices, analyze performance, and understand trends.
Percent Increase
When the new value is higher than the original
Percent Decrease
When the new value is lower than the original
Absolute Change
The actual difference between values
Multiplier
How many times the original value
Common uses for percentage change:
- Stock prices — Track daily/yearly performance
- Sales & revenue — Compare month-over-month or year-over-year
- Price comparisons — How much more or less something costs
- Population growth — Census changes over time
Percentage Change Formula
Percentage Change = ((New Value - Original Value) / |Original Value|) × 100
The absolute value in the denominator ensures correct calculation when dealing with negative original values.
Calculation Examples
Example: Price Increase
Original: $80, New: $100
Change = ((100 - 80) / 80) × 100
= (20 / 80) × 100
= 25% increase
Example: Price Decrease
Original: $200, New: $150
Change = ((150 - 200) / 200) × 100
= (-50 / 200) × 100
= 25% decrease
Frequently Asked Questions
Is a 50% decrease the same as dividing by 2?
Yes! A 50% decrease means the new value is half of the original. Similarly, a 100% increase means the value has doubled.
What does a negative percentage change mean?
A negative percentage indicates a decrease from the original value. For example, -20% means the new value is 20% less than the original.
Can percentage change be more than 100%?
Yes! If something triples, that's a 200% increase. If it quadruples, that's 300%. There's no upper limit for increases.
Can percentage change be more than -100%?
A -100% decrease means the value went to zero. It's not possible to decrease by more than 100% (you can't have less than nothing in most contexts).
Quick Reference
Double (2x): = 100% increase
Triple (3x): = 200% increase
Half (0.5x): = 50% decrease
Quarter (0.25x): = 75% decrease
Use our percentage change calculator above to quickly calculate the change between any two values.