Percentage Decrease Calculator

This calculator works out the percentage decrease between two numbers, showing how much a value has fallen and what that fall looks like as a percentage. It is useful whenever a price, wage, weight, score or measurement has gone down and you need to express that drop clearly, whether that is a sale price, a falling share value, a drop in sales figures, or a reduction in a measurement between two readings. Enter the original value and the new, lower value in the first section, and the calculator instantly returns the percentage decrease, the decrease amount (the original minus the new value), and a full breakdown showing the ratio used in the calculation. If you already know the percentage decrease and want to work forward instead, use the second section: enter the original value and the percentage decrease, and the calculator returns the resulting new value, along with the multiplier and calculation used to reach it. Both sections update live as you type, and the summary line below the results restates the outcome in plain language. The maths follows the standard formula: percentage decrease equals the decrease amount divided by the original value, multiplied by 100. Percentage decrease is always shown as a positive figure representing a fall; if you are not sure whether a value has risen or fallen, use the percentage change calculator instead, which handles both directions.

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Standard formula  Percentage decrease = ((Original − New) / Original) × 100

1. Calculate Percentage Decrease

Please enter a valid number greater than zero.
Please enter a valid number.

2. Or Find New Value from % Decrease

%
Enter a percentage between 0 and 100.

Results

Percentage Decrease
25%
How much it fell
Decrease Amount
50
Original minus New
New Value (from %)
150
After applying % decrease

Percentage Decrease Breakdown

Original value200
New value150
Decrease amount50
Decrease / Original50 / 200 = 0.25
Percentage decrease25%

Reverse Lookup Breakdown

Original value200
Percentage decrease25%
Multiplier1 − 0.25 = 0.75
Calculation200 × 0.75
New value150
Summary: 200 decreased by 25% gives a new value of 150. The decrease amount is 50.

How to Calculate Percentage Decrease

The percentage decrease formula measures how much a value has fallen relative to its starting point. The calculation has two steps:

  1. Find the decrease amount: Decrease = Original value − New value
  2. Divide by the original and multiply by 100: Percentage decrease = (Decrease / Original) × 100

For example, if a product's price drops from $200 to $150, the decrease is $50, and the percentage decrease is (50 / 200) × 100 = 25%.

Formula

What you want to findFormula
Percentage decrease((Original − New) / Original) × 100
Decrease amountOriginal − New
New value from % decreaseOriginal × (1 − Percentage / 100)
Original from new value and %New value / (1 − Percentage / 100)

Worked Example

A jacket was priced at $200. It is now on sale for $150. What is the percentage decrease?

  1. Decrease amount: $200 − $150 = $50
  2. Percentage decrease: ($50 / $200) × 100 = 25%

The jacket has decreased in price by 25%. To verify the reverse: $200 × (1 − 0.25) = $200 × 0.75 = $150.

Common Uses

Percentage Decrease vs Percentage Change

Percentage change can be positive (an increase) or negative (a decrease). Percentage decrease is always expressed as a positive number showing how far a value has fallen. For example, a change from 200 to 150 is a percentage change of −25% or a percentage decrease of 25%. Use the Percentage Change Calculator if you are not sure whether the value has risen or fallen.

Related Calculators

Method: Standard percentage decrease formula: ((Original − New) / Original) × 100. Reverse calculation: Original × (1 − Percentage / 100). No rounding is applied until display.

This calculator is for general mathematical use. Results are based on the values you enter. Verify calculations independently for financial, scientific, or academic purposes.

Frequently asked questions

How do you calculate percentage decrease?

Percentage decrease = ((Original value - New value) / Original value) x 100. For example, if a price drops from 200 to 150, the decrease is 50, and the percentage decrease is (50 / 200) x 100 = 25%. The original value must be greater than zero, and the new value must be less than the original for a true decrease.

What is the difference between percentage decrease and percentage change?

Percentage change can be either positive (an increase) or negative (a decrease). Percentage decrease specifically measures how much a value has fallen as a proportion of the original, and is expressed as a positive number (e.g. '25% decrease' rather than '-25% change'). Use this calculator when you know the value has gone down and you want to express that fall as a percentage.

How do I find the new value after a percentage decrease?

New value = Original value x (1 - Percentage decrease / 100). For example, a 20% decrease from 500 gives 500 x (1 - 0.20) = 500 x 0.80 = 400. This calculator lets you enter either the new value directly or a known percentage decrease to find the new value.

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