To decrease a number by a percentage, multiply it by (1 − percentage ÷ 100). For example, 200 decreased by 15% is 200 × 0.85 = 170.
This is the same engine as the main Percentage Calculator below, focused specifically on the "decrease by %" case — the one most people search for when a price needs a markdown or a value needs to be reduced by a fixed percent.
How it works
Enter the starting number and the percentage you want to subtract. The result is the starting number minus that percentage of itself: new value = original × (1 − percent ÷ 100). This is the same math behind price markdowns and depreciation.
Examples
- 200 decreased by 15% = 170
- 50 decreased by 10% = 45
- 1,000 decreased by 7.5% = 925
Related questions
- What's the formula for percentage decrease?
- New value = original value × (1 − percentage ÷ 100). So a 20% decrease on 150 is 150 × 0.80 = 120.
- Is this the same as a discount calculation?
- Yes — a discount is a percentage decrease applied to a price. The Discount Calculator gives you the same result with labels ("price," "discount") that match a shopping context.