Percentage Decrease Calculator

Find how much a value decreased, or subtract a percentage decrease from any number.

Formula

To decrease a value by a percentage, multiply by 1 minus the percentage as a decimal.

new value = original × (1 - decrease%/100)

Examples

100 decreased by 25% = 100 × 0.75 = 75.
80 decreased by 50% = 40.

Frequently asked questions

Short, practical answers for this calculation.

How do I calculate a percentage decrease?

Subtract the new value from the old value, divide by the old value, then multiply by 100.

How do I subtract 15% from a number?

Multiply the number by 0.85.

Can a decrease be more than 100%?

A simple decrease of 100% reduces a positive value to zero. More than 100% can imply a negative final value in pure math, but may not make sense for prices or quantities.

Is a discount a percentage decrease?

Yes. A discount is a percentage decrease from the original price.

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