Percent Increase / Decrease Calculator
Percent increase and decrease with the correct denominator.
See the exact percent change between any two numbers. Works for both increases and decreases — the sign tells you which.
Part of: Everyday Calculators
- Change
- +25
- Percent
- 25%
- Ratio
- 1.25
How to use
- Enter the starting value.
- Enter the ending value.
- The percent change, absolute delta, and ratio update instantly.
Examples
Before you trust the result
Check the inputs that matter most: dates, rates, units, costs, and any optional fields you skipped. A calculator can only work with the numbers entered here, so use the result as a decision check rather than a final answer when money, health, tax, legal, or safety consequences are involved.
If the result feels surprising, change one input at a time and watch which number moves. That usually shows the real lever behind the decision.
Next up
Frequently asked questions
› Why is percent change not symmetric? Troubleshooting
Going from 100 to 125 is +25%, but going from 125 back to 100 is −20%. The denominator is always the starting value.
› What if the starting value is 0?
Percent change is undefined when the base is 0. Use absolute difference instead.
Tips & related reading
See the Everyday Calculators hub →Tips & how-tos
- How to Calculate Percentage Increase
- How to Calculate Percent Change Fast
- Percent Change and Proportional Reasoning
- When Percent Change Matters in Real Life
- Percent Math Calculator Guide
- Everyday Calculators Guide
- How to Calculate a Percent of a Number
- Percentage Mental Math Tricks
- How to Calculate Age on a Date
- How to Calculate Days Between Two Dates