Percentage Decrease Calculator

Use this free percentage decrease calculator to find out how much a value has fallen in percentage terms. Enter the original value and the new value — the calculator shows the percentage decrease, the actual amount of reduction, and the multiplier instantly. Useful for sale price reductions, cost savings, performance drops, and everyday maths.

📉 Percentage Decrease Calculator




Percentage Decrease Formula

The formula for percentage decrease is:

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

For example: if a price drops from £200 to £150, the decrease is £50, and the percentage decrease is (50 ÷ 200) × 100 = 25%.

How to Calculate Percentage Decrease — Step by Step

  1. Subtract the new value from the original value to get the amount of decrease
  2. Divide the decrease by the original value
  3. Multiply by 100 to convert to a percentage

Percentage Decrease Examples

Original ValueNew ValueDecreasePercentage Decrease
£350 monthly energy bill£280 monthly energy bill£7020%
£120 retail price£90 sale price£3025%
£250,000 property value£237,500 property value£12,5005%
1,200 monthly website sessions960 monthly website sessions24020%
95 kg body weight85.5 kg body weight9.5 kg10%
£45,000 salary£40,500 salary£4,50010%

Where Percentage Decrease Is Used

Percentage decrease is used across shopping, finance, business, and health to measure how much something has fallen relative to where it started:

  • Retail sales and discounts — finding the percentage off during a sale
  • Energy and utility bills — measuring how much costs have fallen after switching tariff
  • Investment losses — calculating how much a portfolio or share price has dropped
  • Business metrics — tracking drops in revenue, traffic, or customer numbers
  • Weight loss and fitness — calculating body weight reduction as a percentage
  • Property values — how much a house has dropped in value since purchase

Percentage Decrease vs Percentage Points

These are often confused. A percentage decrease measures the relative change from the original value. Percentage points measure the absolute difference between two percentages.

Example: if an interest rate falls from 5% to 4%, that is a decrease of 1 percentage point but a 20% percentage decrease (because 1 ÷ 5 × 100 = 20%). Financial news and reports often use both — knowing the difference avoids confusion.

Retail Discount Example

A jacket is reduced from £180 to £126 in a sale. The percentage decrease is:

(180 − 126) ÷ 180 × 100 = 30% discount

To work out the final sale price when you know the discount percentage, use our Discount Calculator.

Frequently Asked Questions

What is percentage decrease?

Percentage decrease shows how much a value has fallen relative to its original amount, expressed as a percentage. A result of 25% means the new value is 25% lower than where it started.

What is the formula for percentage decrease?

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

Can percentage decrease be more than 100%?

No. A value can only decrease by a maximum of 100% — that would mean it has fallen to zero. A percentage decrease greater than 100% is not mathematically possible.

What is the difference between percentage decrease and a discount?

They use the same formula. A discount is simply a percentage decrease applied to a price. The percentage decrease formula gives you the discount rate; the Discount Calculator gives you the final discounted price directly.

How do I reverse a percentage decrease to find the original value?

Divide the new value by (1 − percentage decrease / 100). For example, if a price is now £75 after a 25% decrease: £75 ÷ 0.75 = £100 original price.

Is a 50% decrease the same as halving?

Yes. A 50% decrease means the value has fallen by half of its original amount. A 100% decrease means it has fallen to zero.

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