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Percentage change calculator
Percent increase or decrease from an old value to a new one.
Quick answer
Percentage change measures how much a value rose or fell compared with where it started, and a negative result means a fall. Formula: Percentage change = (new โ old) รท |old| ร 100. A rise from 80 to 100 is a 25% increase.
Read the guide: How to calculate percentage: every common case
Percentage increase
25.00%
- Difference
- 20.00
How is percentage change calculated?
Percentage change compares the size of the move with where you started.
It is not symmetric: a 25% rise needs only a 20% fall to return to the start.
Use it for price rises, marks, population, salary hikes and anything measured at two points in time.
What is the formula for percentage change?
- Percentage change = (new โ old) รท |old| ร 100
- A positive result is an increase and a negative one is a decrease
Can you show a worked example of percentage change?
From 80 to 100: (100 โ 80) รท 80 ร 100 = 25%. From 100 back to 80 is (80 โ 100) รท 100 ร 100 = โ20%, so the way back is a smaller percentage.
What is the percentage change between common values?
Percentage change = (new โ old) รท old ร 100. A negative result is a fall.
| Old value | New value | Change |
|---|---|---|
| 80 | 100 | +25% |
| 100 | 80 | โ20% |
| 50 | 75 | +50% |
| 200 | 150 | โ25% |
| 1,000 | 1,200 | +20% |
| 1,200 | 1,000 | โ16.6666666667% |
Common questions
How do I calculate percent increase?
Subtract the old value from the new, divide by the old value and multiply by 100.
Why is a 50% rise then a 50% fall not back to the start?
The fall is worked out on the larger number. 100 up 50% is 150, and 150 down 50% is 75.
What if the old value is 0?
The percentage is undefined, so the calculator asks for a different starting value.
How is this different from percentage difference?
Percentage change has a clear before and after. Percentage difference compares two values with no order, using their average as the base.