Percentage Increase Calculator
Going from 100 to 125 is a 25% increase. Going from 80 to 60 is a 25% decrease. This calculator takes a starting value and an ending value and returns the percentage change between them, labeled as an increase or a decrease. Use it for price changes, salary raises, traffic growth, or any before and after comparison.
Quick answer
Percentage change = (final - initial) / initial x 100.
Change
25% increase
Difference
25
What this tells you
- •Percentage change = (final - initial) / initial x 100.
- •A positive result is an increase and a negative result is a decrease.
- •The change is always measured against the starting value.
- •A 50% increase followed by a 50% decrease does not return to the start.
How to Use
- 1Enter the initial value, the before number.
- 2Enter the final value, the after number.
- 3Read the percentage change and its direction below.
How It Works
Formula
% change = (final - initial) / initial x 100Subtract the initial value from the final value, divide by the initial value, then multiply by 100. From 100 to 125 that is 25 divided by 100 times 100, a 25% increase. The division uses the starting value, which is why the same 25 point move from 125 back to 100 is only a 20% decrease.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Price rises from $100 to $125
The difference of 25 divided by the starting 100 is 0.25, a 25% increase.
Traffic drops from 80 to 60
The difference of -20 divided by 80 is -0.25, a 25% decrease.
Percentage Change Examples
How the same numbers read in each direction.
| From | To | Change |
|---|---|---|
| 100 | 125 | 25% increase |
| 125 | 100 | 20% decrease |
| 50 | 75 | 50% increase |
| 75 | 50 | 33.33% decrease |
| 200 | 220 | 10% increase |
| 40 | 100 | 150% increase |
The percentage differs by direction because the change is measured against the starting value.
Common mistakes
- Dividing by the final value instead of the initial value. The starting number is always the base.
- Treating percentage points and percent as the same. Going from 10% to 15% is a 5 point rise but a 50% increase.
- Expecting reverse symmetry. A 25% increase is undone by a 20% decrease, not 25%.