Percentage Change Calculator
Enter the old value and the new value to see the percentage increase or decrease.
Quick answer: Percentage change = (new − old) ÷ old × 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = 25%, a 25% increase.
Percentage change from X to Y
How to use it
- Fill in the two boxes of the calculator you need.
- The answer updates as you type, in large numbers.
Examples
| From | To | Change |
|---|---|---|
| 50 | 60 | +20.0% |
| 80 | 100 | +25.0% |
| 200 | 150 | -25.0% |
| 40 | 10 | -75.0% |
| 100 | 250 | +150.0% |
| 60 | 66 | +10.0% |
A change from a smaller number to a larger one is an increase. The percentage is always based on the old value, so an increase of 100% doubles a number but a decrease of 50% halves it.
What people use it for
- Sales, discounts and tax
- Grades and test scores
- Pay rises and price changes
- Recipes and measurements
- Statistics and homework
Questions
What is the formula for percentage change?
(New value − old value) ÷ old value × 100.
Why is a 50% drop not undone by a 50% rise?
The two changes use different bases. A 50% drop from 100 gives 50, and a 50% rise from 50 gives 75, not 100.
Can a percentage change be over 100%?
Yes. If a value more than doubles, the increase is more than 100%.
Is it free?
Yes. No sign-up, no install and no limit.
Is anything saved or sent?
No. Everything runs in your browser. Only your own best score, where a page shows one, is kept on your device.
Last updated 2026-10-24. Free to use, no sign-up. Made by ficklestudio26.