Percentage Change Calculator
Calculate percentage change, increase or decrease, a percentage of a number, and what percent one value is of another. Free instant results.
Your results
Calculation breakdown
- Percentage of a number
- (percentage ÷ 100) × value
- Percentage change
- ((to − from) ÷ |from|) × 100
- Increase / decrease by %
- base × (1 ± percentage ÷ 100)
- X is what % of Y
- (X ÷ Y) × 100
How this calculator works
This all-in-one percentage calculator shows four common calculations at once: percentage of a number, percentage change between two values, increasing or decreasing a value by a percentage, and working out what percentage one number is of another.
How to calculate percentage change
Subtract the starting value from the new value, divide the difference by the absolute starting value, then multiply by 100. A positive answer is an increase and a negative answer is a decrease.
For example, a price moving from $80 to $100 has increased by $20. Dividing $20 by the $80 starting value gives 0.25, so the percentage increase is 25%.
- Percentage change = (new − original) ÷ |original| × 100
- Always divide by the original value, not the new value
- A zero starting value has no defined percentage change
Percentage change versus percentage-point change
Percentage change measures a difference relative to the starting value. Percentage-point change is the direct subtraction between two values that are already percentages, such as a rate rising from 10% to 12% by 2 percentage points.
The same move from 10% to 12% is a 20% relative increase because the 2-point change is divided by the 10% starting rate. State which measure you are using whenever the inputs are percentages.
Frequently asked questions
How is percentage change calculated?
It is the difference between the two values, divided by the absolute value of the starting number, multiplied by 100.
Can percentage change be negative?
Yes. A negative result means the value has decreased.
Why do all four results show at once?
Each section uses its own inputs, so you can use the calculator for multiple everyday percentage questions without resetting it.