Percentage Decrease Calculator

Our free online percentage decrease calculator helps you find the percentage decrease from a starting value to a final value. Whether you are tracking price drops, energy savings, or weight loss, this tool provides accurate results with step-by-step solutions.

What is Percentage Decrease?

Percentage decrease measures how much a value has declined relative to its original amount. The formula calculates the difference between the starting and final values, divides by the absolute value of the starting value, and multiplies by 100.

\[ \text{Percentage Decrease} = \frac{\text{Starting Value} - \text{Final Value}}{|\text{Starting Value}|} \times 100 \]

How to Calculate Percentage Decrease

1. Find the difference: Subtract the final value from the starting value
2. Divide by the original: Divide the difference by the absolute value of the starting value
3. Convert to percentage: Multiply the result by 100

Example: Energy Savings

You have a lamp with a 60-watt traditional light bulb. You switch to an LED bulb that uses 8 watts. What is the percentage decrease in energy use?

\[ \frac{60 - 8}{|60|} \times 100 = \frac{52}{60} \times 100 = 86.67\% \]

You reduced energy usage by 86.67%.