How it works
The original value is multiplied by 1 minus the percentage expressed as a decimal, so a 20% decrease multiplies by 0.80.
Formula: New value = original × (1 − percentage ÷ 100)
Examples
A discounted price
100 decreased by 20% is 100 × 0.80 = 80.
A larger decrease
50 decreased by 40% is 50 × 0.60 = 30.
Things to keep in mind
- This calculator finds the value after a decrease. To go the other way — working out what a value was before a known decrease — use the reverse-percentage mode on the main Percentage Calculator instead.
- A percentage decrease of 100% or more always gives zero or a negative result, since decreasing a value by 100% removes all of it. This is a correct, if unusual, answer rather than an error.