Percentage Decrease Calculator
Calculate how much a value has decreased as a percentage. Free online percentage decrease calculator from original and new values.
((Original − New) / |Original|) × 100
((200 − 150) / 200) × 100 = 25.00%
25.00%
Decrease
Original Value
200
Decreased Value
150
Amount Decreased
50.0000
New / Original Ratio
0.7500
How Does the Percentage Decrease Calculator Work?
Enter the original value and the decreased value. The calculator finds the amount decreased and computes the percentage using the formula: ((Original − New) / |Original|) × 100. The result is always shown as a positive percentage, and the new/original ratio shows how much of the original value remains.
Example
If a price drops from $200 to $150, the percentage decrease is ((200 − 150) / 200) × 100 = 25%, and the new/original ratio is 150 / 200 = 0.75. If the new value ends up higher than the original, the tool flags it as an increase instead of a decrease.
Common Use Cases
- Calculating the size of discounts and markdowns.
- Measuring reductions in costs, expenses, or inventory.
- Tracking decreases in website traffic, sales, or engagement.
- Reporting weight loss, grade drops, or other decline metrics.
FAQs
What if the new value is greater than the original value?
Then it is an increase, not a decrease. The calculator still shows the percentage (positive) and labels it as an increase, so no negative numbers appear.
What if the original value is zero?
Division by zero is undefined. If the original value is zero, a percentage cannot be calculated meaningfully because any change from zero is technically infinite.
What does the new/original ratio mean?
The ratio tells you what fraction of the original value remains. A ratio of 0.75 means the new value is 75% of the original, which corresponds to a 25% decrease.