Percentage Decrease: Formula and Examples
A compact guide to percentage decrease with the formula, worked examples, and the most common mistakes.
Percentage decrease in one line
Percentage decrease tells you how much a value went down compared with the original value.
The formula is:
Percentage decrease = ((original - new) / original) * 100
How to calculate percentage decrease
- Subtract the new value from the original value.
- Divide the result by the original value.
- Multiply by 100.
Example 1
A price drops from 80 to 60.
- Difference: 80 - 60 = 20
- Divide by original: 20 / 80 = 0.25
- Convert to percent: 0.25 * 100 = 25%
The percentage decrease is 25%.
Example 2
Website traffic falls from 1,200 visits to 900 visits.
- Difference: 1,200 - 900 = 300
- Divide by original: 300 / 1,200 = 0.25
- Convert to percent: 25%
Quick rule
Always divide by the original number, not the new number. That is the mistake people make most often.
Percentage decrease vs percentage points
If a rate drops from 12% to 9%, that is:
- 3 percentage points of absolute change
- 25% decrease relative to the original 12%
These are both correct, but they mean different things.
Common uses
- Discounts and sale prices
- Revenue or traffic drops
- Cost reductions
- Comparing performance over time
FAQ
Can percentage decrease be more than 100%?
No. A value can fall to zero, which is a 100% decrease, but not lower in normal percentage change calculations.
What is the difference between decrease and discount?
A discount is one practical use of percentage decrease. The math is the same when you compare the old price with the new price.
Can I calculate it with a tool?
Yes. You can use calculate-percentage.online to work out percentage change quickly and avoid arithmetic mistakes.