Percentage Change Calculator
See the percent increase or decrease between two numbers. Free, instant and no sign-up.
How this percentage change calculator works
Enter the old value and the new value. The calculator shows the difference between them and the percent change, and tells you whether it is an increase or a decrease. It works for prices, wages, grades, population, website traffic and anything else that changes over time.
The formula
Percent change = (new value − old value) ÷ old value × 100. A positive result is an increase and a negative result is a decrease.
Example
A price that goes from $80 to $100 rises by $20, which is 20 ÷ 80 × 100 = 25%. If the price then falls from $100 back to $80, the change is −20 ÷ 100 × 100 = −20%. The two percentages differ because each is measured against a different starting value.
Percent change vs percentage points
If a sales tax rate goes from 5% to 8%, it rose by 3 percentage points, but the percent change is 3 ÷ 5 × 100 = 60%. Percentage points describe the simple gap between two percentages, while percent change compares them to the starting percentage.
Tips
The old value is always the starting point. Swapping the two values gives a different answer. See our guide to calculating percentage change for more examples, or use the Percentage Calculator to take a percent of a number.
Frequently asked questions
Why can a 25% increase and a 20% decrease be the same change?
The same dollar gap is measured against a bigger or smaller starting number. $80 to $100 is up 25%, and $100 to $80 is down 20%.
What if the old value is zero?
Percent change is undefined when the starting value is zero, so the calculator asks for a different old value.
Is my data saved?
No. Everything stays in your browser.