Calculators

How to Calculate Percentage Decrease

Learn how to calculate percentage decrease with the formula, a step-by-step example, and common mistakes to avoid.

Brekzy Team Published September 7, 2026

On this page
  1. What Is Percentage Decrease?
  2. Percentage Decrease Formula
  3. Step-by-Step Example
  4. Practical Examples
  5. Common Mistakes to Avoid
  6. Using the Percentage Decrease Calculator

Percentage decrease tells you how much a value has dropped, expressed as a percentage of where it started. It is used to describe everything from price reductions and revenue declines to weight loss and falling measurements.

What Is Percentage Decrease?

Percentage decrease measures the shrinkage from an original value to a new, smaller value. Like percentage increase, it is always calculated relative to the original value, not the new one.

Percentage Decrease Formula

Percentage Decrease = ((Original Value − New Value) ÷ Original Value) × 100

The result is positive whenever the new value is smaller than the original. If the new value is larger, the same formula produces a negative number, which represents an increase rather than a decrease.

Step-by-Step Example

Original Price: $200
New Price: $150

  1. Subtract: 200 − 150 = 50
  2. Divide by the original value: 50 ÷ 200 = 0.25
  3. Convert to a percentage: 0.25 × 100 = 25%

Result: The price decreased by 25%.

Practical Examples

A product discount is really just a percentage decrease applied to a price. The same formula works for any quantity that goes down.

Scenario Original Value New Value Percentage Decrease
Product discount $60 $45 25%
Revenue decrease $50,000 $42,500 15%
Weight loss 180 lbs 162 lbs 10%
Price reduction $60 $45 25%

Note the distinction: “percentage decrease” is the general mathematical concept for any two values, while “discount” specifically refers to a price reduction. Every discount is a percentage decrease, but not every percentage decrease is a discount. For pricing scenarios specifically, see How to Calculate a Discount.

Common Mistakes to Avoid

  • Using the new value as the denominator. Going from $200 to $150, dividing 50 by 150 gives 33.3%, not 25%. The denominator must always be the starting value.
  • Confusing the decrease percentage with the remaining percentage. A 25% decrease means 75% of the original value remains, not that the new value equals 25% of the original.
  • Mixing up percentage points and percentages. A drop from 40% to 30% is a 10 percentage-point decrease, but it is a 25% decrease relative to the original 40% ((40 − 30) ÷ 40 × 100 = 25%).

Using the Percentage Decrease Calculator

For an instant, error-free result, use the Percentage Decrease Calculator. Enter the original and new values and it calculates the percentage decrease automatically. To calculate growth instead, see How to Calculate Percentage Increase.

Try it yourself

Percentage Decrease Calculator

Try our Percentage Decrease Calculator →

Frequently Asked Questions

What is the formula for percentage decrease?

Percentage Decrease = ((Original Value − New Value) ÷ Original Value) × 100. Subtract the new value from the original value, divide by the original value, then multiply by 100.

Can a percentage decrease be more than 100%?

For quantities that cannot go below zero, such as price, weight, or count, a percentage decrease maxes out at 100%, which happens when the new value is zero. This is different from percentage increase, which has no upper limit.

What is the difference between percentage decrease and a discount?

A discount is a percentage decrease applied specifically to a price in a commercial context. Percentage decrease is the broader mathematical concept and applies to any two values, whether that is a price, a population, a measurement, or a score.

How is percentage decrease different from percentage points?

Percentage points measure the raw difference between two percentage figures. Percentage decrease measures that same change relative to the original percentage. A drop from 40% to 30% is 10 percentage points but a 25% decrease.

What happens if the original value is zero?

Percentage decrease cannot be calculated when the original value is zero, because the formula requires dividing by that value.

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