What is the formula for percentage decrease?

The formula is: ((Original Value − New Value) / Original Value) × 100. The result is the percentage by which the value decreased.

What if the new value is higher than the original?

If the new value is greater than the original, the result is a percentage increase, not a decrease. The calculator will display a warning and show the increase instead.

What happens if the original value is zero?

Division by zero is undefined. If the original value is 0, the calculator shows an error because percentage decrease from zero cannot be computed.

Is percentage decrease the same as percentage change?

Percentage decrease is a specific case of percentage change where the value goes down. The formula is the same but focuses on reductions. A general percentage change can be either an increase or decrease.

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

Multiply the original value by (1 − percentage / 100). For example, a 20% decrease from 500 gives 500 × 0.80 = 400. You can verify this by entering 500 and 400 into this calculator.

What does "remaining percentage" mean?

Remaining percentage is the new value expressed as a percent of the original. For example, if a price drops by 25%, the remaining percentage is 75% — you are paying 75% of the original price.

Why doesn't a 50% drop followed by a 50% rise get back to the start?

Because each percentage is taken from a different base. 100 drops 50% to 50, and a 50% rise on 50 only adds 25, giving 75. To recover from a 50% drop you need a 100% rise.

How do I find the original value before a decrease?

Divide the new value by (1 − percentage ÷ 100). A price of $68 after 15% off was $68 ÷ 0.85 = $80 before the discount.

Percentage Decrease Calculator

Enter an original value and a new (lower) value to instantly find the percentage decrease and the absolute amount dropped.

Percentage decrease = (original − new) ÷ original × 100.

Enter Values

Original Value

The starting or baseline number

New Value

The ending or reduced number

Formula

% Decrease = ((Original − New) / Original) × 100

Result

Enter values and click Calculate Decrease

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Quick answer

Percentage decrease = (original − new) ÷ original × 100. Going from 80 to 60 is a drop of 20, and 20 ÷ 80 = 0.25, so the decrease is 25%.

Examples

Original	New	Drop	Percent decrease
80	60	20	25%
1,250	1,000	250	20%
3,200	2,720	480	15%
49.99	34.99	15	30.01%
150	75	75	50%

Enter the two values.

Summary

This calculator computes the percentage decrease between two numbers. Enter the original (starting) value and the new (lower) value, and it instantly shows the percent decrease, the absolute amount dropped, and the remaining value as a percentage of the original. It is ideal for comparing prices, discounts, salary cuts, weight loss, or any numeric measurement that has gone down.

How it works

Enter the original value (the starting number) in the first field.
Enter the new value (the lower number) in the second field.
The calculator applies the formula: ((Original − New) / Original) × 100.
The result shows the percentage decrease, the absolute drop, and the remaining percentage.
Use the Copy button to copy the full result summary to your clipboard.

Use cases

Calculate a sale discount or price reduction on a product.
Find how much a salary or wage decreased year over year.
Measure the drop in website traffic, revenue, or user counts.
Determine the percentage weight lost during a fitness program.
Track a decline in test scores, production output, or inventory.
Compute a stock price drop from a previous high.
Verify a quoted discount percentage from a retailer.
Analyze a reduction in energy usage or emissions.

Frequently Asked Questions

Last updated: 2026-06-04 · Reviewed by Nham Vu