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Percentage Decrease Calculator

The Percentage Decrease Calculator finds how much a value fell, in percent, between an original and a new number — such as a discount, a drop in price or a loss of weight. If the new value is higher, it reports the percentage increase instead.

What this means

Percentage decrease measures the drop relative to the starting value. A fall from 80 to 60 is a 25% decrease, because 20 is 25% of the original 80.

How we calculate it

Formula

Decrease % = (Original − New) ÷ |Original| × 100.

Worked example

A product drops from $80 to $60:

  1. 1Decrease = 80 − 60 = 20
  2. 220 ÷ 80 = 0.25
  3. 30.25 × 100 = 25% decrease

Important assumptions

  • Both values must be positive for a meaningful percent decrease.

Frequently asked questions

How do I calculate a 20% discount?

Multiply the original price by 0.80. An $80 item becomes $64 after a 20% discount.

What if the new value is higher?

This calculator reports it as a percentage increase instead of a decrease.

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