Reduction calculator

Percentage Decrease Calculator

Reduce a starting value by any percentage and see exactly how much is removed and what remains.

Live calculation
🔒
Private by design

Your numbers are calculated in this browser. No account or database is required.

How this calculator works

New value = original × (1 − percentage ÷ 100)

Use percentage decrease for reductions, shrinkage, markdowns, budget cuts and other changes where you already know the percentage to remove.

Example: decrease 500 by 18%

18% of 500 is 90. Subtract 90 from 500 to get 410.

Frequently asked questions

What happens at a 100% decrease?

A 100% decrease reduces a positive starting value to zero.

Is a 20% decrease followed by a 20% increase back to the start?

No. The second 20% is applied to the smaller value, so the final value is 96% of the original.