Percentage change formula
Use (New − Original) ÷ Original × 100. A positive result is an increase and a negative result is a decrease.
Increase example
If a value rises from 80 to 100, the change is 20. Divide 20 by 80 and multiply by 100. The increase is 25%.
Decrease example
If a value falls from 100 to 80, the change is −20. Dividing by the original 100 gives −20%, which means a 20% decrease.
Try different values with the Percentage Change Calculator.
Quick answer
Calculate percentage increase, decrease and percent change between two values. Use the values and units shown by the tool, review the result, and keep the original inputs available if you need to compare another scenario.
Practical checklist
- Confirm the units, dates, rates or source values before calculating.
- Use consistent units and avoid rounding intermediate values too early.
- Run a second scenario when you need to understand how one input changes the result.
- For regulated fees, taxes, provider rules or professional decisions, verify the current official rule before relying on the result.
Try the related ToolViso tool
Use the Percentage Change Calculator to check the calculation or conversion directly in your browser. No signup is required.
Frequently asked questions
Is Percentage Change Calculator free to use?
Yes. The tool is available without signup or a paid account.
Does this tool work on mobile devices?
Yes. The interface is responsive and is designed to work in modern mobile and desktop browsers.
Can I use the result for official or financial decisions?
Use the result as a practical estimate. Confirm legally, financially or operationally important figures with the relevant official source, provider or professional.