Understanding Percentage Decrease
A percentage decrease calculates a new value that is a certain percentage less than the original. This is commonly used for discounts, depreciation, population decline, price reductions, and loss calculations.
Percentage Decrease Formulas
New Value
Calculate the final value after applying the decrease:
Amount Decreased
Calculate just the amount of the decrease:
Alternative Method
First find the decrease, then subtract from original:
How to Calculate Percentage Decrease
- Convert the percentage to a decimal by dividing by 100.
- Multiply the original value by the decimal to find the decrease amount.
- Subtract the decrease amount from the original to get the new value.
- Alternatively, multiply the original by (1 - percentage/100) in one step.
Common Examples
- Sale discount: A $150 item is 30% off. Decrease = $150 x 0.30 = $45. Sale price = $105.
- Depreciation: A $25,000 car depreciates 15% per year. After 1 year = $25,000 x 0.85 = $21,250.
- Weight loss: A 200 lb person loses 10% body weight = 200 x 0.10 = 20 lbs lost, new weight = 180 lbs.
Percentage Decrease vs. Percentage Change
Percentage decrease is a specific type of percentage change where the value goes down. While percentage change can be positive (increase) or negative (decrease), this calculator focuses specifically on decreases. The percentage decrease is always expressed as a positive number representing how much was lost.
Successive Decreases
When applying multiple percentage decreases in sequence, you cannot simply add the percentages. For example, two successive 10% decreases result in a total decrease of 19% (not 20%), because the second decrease is applied to the already-reduced value.