About the Percentage Decrease Calculator
Calculate the percent decrease from an original value to a new value, or reduce a number by a percentage.
Also known as: percent decrease, decrease by percentage, percent reduction, subtract percentage.
How to use this calculator
- Enter calculate and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Open “Step-by-step” to see how the answer was worked out.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Decrease % = (Original − New) ÷ Original × 100
Worked example
Using the values pre-filled in the calculator above:
- Calculate: Percent decrease from A to B
- Original value (A) = 120
- New value (B) = 90
the calculator returns:
- Percentage decrease: 25%
- Absolute change: 30
Working
(120 − 90) ÷ 120 × 100 = 25%