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.

Percentage Decrease Calculator

Name: Percentage Decrease Calculator
Availability: InStock
Author: Nham Vu

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

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

Copied!

Summary

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

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: 2026-06-09 · Reviewed by Nham Vu