Percentage Decrease Calculator – Find Percent Decline
Calculate the percentage decrease from an original value to a new value. Enter both numbers and get the percent decline instantly. Useful for discounts, shrinkage, and decline metrics.
Percentage Decrease Calculator
Calculate the percentage decrease from an original value to a new value. Formula: ((original − new) ÷ original) × 100.
How the percentage decrease formula works
% Decrease = ((Original Value − New Value) / Original Value) × 100
The result is the percentage by which the value decreased. If the new value is greater than the original, use the percentage increase calculator instead.
Understanding percentage decrease and when to use it
Percentage decrease measures how much a value has fallen from its original level. When a quantity goes from one value to a lower value, the percentage decrease tells you how much it declined relative to the starting point. For example, if a product's price drops from 200 to 160, the decrease is 20%—meaning the new price is 20% less than the original.
The formula divides the absolute decrease (original minus new) by the original value and multiplies by 100. This ensures consistent interpretation: a 20 drop from 100 to 80 is 20%, and a 20 drop from 200 to 180 is 10%. The percentage reflects the relative change, not just the absolute change.
Common uses include calculating discounts, measuring weight loss, tracking sales declines, and analyzing cost reductions. The percentage decrease calculator handles the math for you—just enter the original and new values. For changes that can go either way, use the percentage change calculator.