Percentage Decrease Calculator
Decrease a number by a percentage, for discounts, depreciation and cuts.
About the Percentage Decrease Calculator
Enter a starting value and the percentage to take off. The calculator gives the new value, the amount removed, the multiplier, and the percentage increase needed to get back. Use it for discounts, depreciation, weight loss or budget cuts.
To take off a percentage, multiply by 1 minus the percentage as a decimal: 15% off 200 is 200 × 0.85 = 170. Getting back to 200 then needs a 17.65% increase.
The formula
New = Old × (1 − p ÷ 100)
- p
- the percentage
- 1 − p ÷ 100
- the multiplier
Worked example
Decrease 200 by 15%
- 15% of 200 = 30
- 200 − 30 = 170, or 200 × 0.85
- To get back to 200: increase 170 by 17.65%
Questions people ask
Is 50% off then 50% off free?
No: 0.5 × 0.5 = 0.25, so you still pay 25%.
How do I reverse a decrease?
Divide by (1 − p/100), not multiply by (1 + p/100).
How do I find the price before a discount?
Divide the sale price by the multiplier: 170 ÷ 0.85 = 200.