Percentage Increase Calculator
Find the percentage increase or decrease between two numbers, or increase and decrease a number by a percentage. Free and instant.
Percentage change between two numbers
Increase or decrease a number by a percentage
How to use the Percentage Increase Calculator
- For percentage change, enter the starting value and the ending value, then click Calculate % change.
- A positive result is an increase and a negative result is a decrease.
- To apply a percentage, enter a number and a percentage, then click Increase by % or Decrease by %.
- Read the result and the working shown underneath.
Frequently asked questions
How do you calculate percentage increase?
Subtract the old value from the new value, divide by the old value, then multiply by 100. Going from 80 to 100 is (100 – 80) / 80 x 100 = 25%.
How do you calculate percentage decrease?
Use the same formula. A negative result means a decrease. Going from 100 to 80 is (80 – 100) / 100 x 100 = -20%.
Why is a 25% increase not reversed by a 25% decrease?
The two percentages apply to different bases. Increasing 80 by 25% gives 100, and decreasing 100 by 25% gives 75, not 80. To undo a 25% rise you need a 20% fall.
How do I increase a number by a percentage?
Multiply the number by 1 plus the percentage as a decimal. To add 15% to 250, calculate 250 x 1.15 = 287.50.
What if the starting value is zero?
The percentage change is undefined, because you cannot divide by zero. Use the absolute difference instead.