Percentage Change Calculator
By Santaji GadepatilinUpdated October 27, 2026
Percentage change shows how much a value has gone up or down compared with where it started. It is used for prices, salaries, sales and almost any comparison over time.
Percentage change (%) vs New value — other inputs held at your current values.
How to use the percentage change calculator
Enter the original and new values to get the percentage change and the difference. You can also work backwards: enter the original value and a percentage change (for example −20%) to find the new value.
Percentage change formula
percentage change = (new − original) ÷ original × 100
Example: a price rises from 80 to 92.
- Difference = 92 − 80 = 12
- Percentage change = 12 ÷ 80 = 0.15 = 15% increase
Increase or decrease?
| Result | Meaning |
|---|---|
| Positive (for example +15%) | The value increased |
| Zero | No change |
| Negative (for example −13%) | The value decreased |
Percentage change is not symmetric
Going up 15% and then down 15% does not bring you back to where you started:
- 80 + 15% = 92
- 92 − 15% = 78.2
That is because each change is measured against a different base. To undo a 15% rise you need a fall of 13.04%.
Percentage change vs percentage points
If an interest rate moves from 4% to 5%, it rose by 1 percentage point, which is a 25% increase in the rate itself. News reports often mix these up — this calculator gives the percentage change.
Percentage change examples
| From | To | Change |
|---|---|---|
| 50 | 75 | +50.0% |
| 75 | 50 | -33.3% |
| 100 | 250 | +150.0% |
| 200 | 150 | -25.0% |
| 1200 | 1380 | +15.0% |
| 40 | 10 | -75.0% |
Percentage difference (no “original” value)
When neither value is the starting point — comparing two shops’ prices, say — use percentage difference, which divides by the average:
% difference = |a − b| ÷ ((a + b) ÷ 2) × 100
For 80 and 92 that is 12 ÷ 86 × 100 = 13.95%.
Reversing a percentage change
To undo a change, you need a different percentage:
| Change | To get back you need |
|---|---|
| +10% | −9.09% |
| +25% | −20% |
| +50% | −33.3% |
| −20% | +25% |
| −50% | +100% |
This is why a stock that falls 50% must double to recover.
Over several years
For growth over several years, the yearly average is not the total change divided by the number of years. Use the CAGR calculator for the compound annual rate.
Frequently asked questions
What is the formula for percentage change?
Percentage change = (new − original) ÷ original × 100. From 80 to 92 is (92 − 80) ÷ 80 × 100 = 15%.
Is a negative result a decrease?
Yes. A negative percentage change means the value fell. From 92 back to 80 is −13.04%.
Why is the change from 80 to 92 not the same as from 92 to 80?
Percentage change is always measured against the starting value. 12 is 15% of 80 but only 13.04% of 92.
How do I calculate a percentage increase?
(new − old) ÷ old × 100. From 80 to 92: 12 ÷ 80 × 100 = 15%.
How do I find the original value before a percentage increase?
Divide the new value by (1 + change). After a 15% rise to 92, the original was 92 ÷ 1.15 = 80.