Percentage Change Calculator
Enter a starting value and a new value to see the percentage increase or decrease.
Result
- Change
- 20
- Percentage change (signed)
- 25%
- Percentage change = (new − old) ÷ |old| × 100.
How to use Percentage Change Calculator
- Enter the starting value.
- Enter the new value.
- Read the percentage increase or decrease.
About this tool
Percentage change shows how much a value moved compared with where it started. From 80 to 100 is a rise of 20, which is 25% of 80.
The starting value cannot be zero, because a percentage change from zero is not defined. A fall from 100 to 75 is a 25% decrease, but a rise from 75 back to 100 is about 33.3%, because the starting value is different.
How it is calculated
Percentage change = (new − old) ÷ |old| × 100.
Worked examples
- 80 to 100: +25%
- 100 to 75: −25%
- 75 to 100: +33.3333%
Tips for better results
- A percentage increase and the matching decrease are not equal.
- For a difference between two peers, with neither as the base, use a different formula.
Frequently asked questions
How do you calculate percentage increase?
Subtract the old value from the new, divide by the old value, and multiply by 100.
Why is a 25% fall not undone by a 25% rise?
The second percentage applies to the smaller number, so it adds back less.
Are my numbers saved or sent anywhere?
No. The calculation runs in your browser on your own device. Nothing you type is sent to Paul Digital or any other server.
Related tools
- Percentage Calculator
- Discount Calculator
- Average Calculator
- ROI Calculator (Return on Investment)
- All web tools
Privacy
The calculation runs in your browser on your own device. The numbers you type are not sent to Paul Digital or any other server. Results are estimates from the numbers you enter and are not financial, tax or legal advice.