Percent Decrease Calculator
Find the percent decrease or the decrease in a value by entering the known values below.
Result:
Steps to Solve Percent Decrease
Steps to Solve Decrease in Value
On this page:
Joe is the creator of Inch Calculator and has over 20 years of experience in engineering and construction. He holds several degrees and certifications.
Pateakia has worked in education for 15 years and has three degrees, including a PhD, Master's degree, and Bachelor's degree. She specializes in mathematics.
How to Find Percent Decrease
Percent decrease is the reduction of a value expressed as a percentage. It is the percentage of change from an initial value to a smaller final value.
The percentage of decrease is found using a formula.
Percent Decrease Formula
The formula to calculate the percentage of decrease is the difference between the initial and final value divided by the initial value.
p = final – initial / |initial| × 100
Thus, the decrease in value is equal to the final value minus the initial value, divided by the absolute value of the initial. Multiply by 100 to find the percentage.
For example, let’s calculate the percentage of reduction from 120 to 80.
p = 80 – 120 / |120| × 100
p = -40 / 120 × 100
p = -0.3333 × 100
p = -33.33%
How to Calculate Reduction by a Percentage
When the percent decrease is known, you can calculate the reduction of a value by multiplying the initial value by the percentage and adding it to the initial value.
final = initial – (initial × p / 100)
The final value is equal to the initial value times the reduction percentage divided by 100, plus the initial value.
For example, let’s calculate the reduction of 150 by 20%
final = 150 – (150 × 20 / 100)
final = 150 – (150 × .2)
final = 150 – 30
final = 120
Use our percent increase calculator to find the increase in a value.
Frequently Asked Questions
Is percentage decrease the same as percentage change?
Percent difference is an expression of the difference between two values rather than the change. Percent of change, on the other hand, is an expression of the amount of change from an old value to a new value.
What is the percent decrease when a quantity is reduced in half?
When the quantity is reduced in half, the percent decrease is 50%.
Is percent decrease positive or negative?
While the solution to the calculation can be negative, the percent decrease is represented as positive. For the example mentioned above, the solution is p = -33.3. Therefore, there is a 33.3% decrease.