Price falls from $100 to $80
A product price drops from $100 to $80.
Calculation: (100 − 80) ÷ 100 × 100 = 20%
Answer: The price decreased by 20%.
Percentage Decrease Calculator
Enter an original value and a new value to find the percentage decrease. The calculator shows the result, formula, and calculation steps.
Calculate percentage decrease
Example: Find the percentage decrease from 100 to 80
How to calculate percentage decrease
Subtract the new value from the original value. Then divide the difference by the original value and multiply by 100.
Percentage decrease formula
(original value − new value) ÷ original value × 100
The original value is the baseline for the calculation. If the new value is higher than the original value, use the percentage increase calculator instead.
Examples
Visitors fall from 1,200 to 900
A website receives 1,200 visitors in one month and 900 the next month.
Calculation: (1,200 − 900) ÷ 1,200 × 100 = 25%
Answer: Traffic decreased by 25%.
Inventory falls from 500 to 425 units
A warehouse inventory decreases from 500 units to 425 units.
Calculation: (500 − 425) ÷ 500 × 100 = 15%
Answer: Inventory decreased by 15%.
Frequently asked questions
How do I calculate a percentage decrease?
Subtract the new value from the original value, divide the result by the original value, and multiply by 100.
What is the percentage decrease from 100 to 80?
The difference is 20. Divide 20 by the original value of 100, then multiply by 100. The percentage decrease is 20%.
Can the original value be zero?
No. Percentage decrease cannot be calculated from a zero original value because the formula requires division by the original value.
What if the new value is higher than the original value?
That is a percentage increase rather than a decrease. This calculator identifies the increase and points you to the relevant tool.