# Percentage Decrease Calculator

## Calculator Use

The Percentage Decrease Calculator finds the decrease from one value to another in terms of a percentage.

Enter starting value and final value to find percentage decrease.

## How to Calculate Percentage Decrease

- Subtract starting value minus final value
- Divide that amount by the absolute value of the starting value
- Multiply by 100 to get percent decrease
- If the percentage is negative, it means there was an increase and not an decrease.

## Percentage Decrease Formula

You can use the percentage decrease formula for any percent decrease calculation:

## Example Problem: Percentage Decrease

You have a lamp with a 60-watt traditional light bulb. Your lamp uses 60 watts of electricity per hour. You're considering replacing the bulb with an LED light bulb that uses 8 watts of electricity per hour. What is the percentage decrease in the lamp's hourly energy use if you switch to an LED light bulb?

Percentage Decrease = [ (Starting Value - Final Value) / |Starting Value| ] × 100

60 - 8 = 52

52 / 60 = 0.8667

0.8667 × 100 = 86.67%

So if you switch to an LED light bulb your lamp will use 86.67% less energy per hour.

### Related Calculators

Use the Percentage Increase Calculator to find the percent increase from one value to another.

Use the Percent Difference Calculator when you are comparing two values and want to find the percentage difference between them.

The Percent Change Calculator finds the change between two numbers as a percentage. It is similar to finding percentage increase or percentage decrease but it doesn't label the change as an increase or a decrease.