How to use the Percentage Decrease Calculator
- To reduce a number by a percentage, enter the number and the percentage in the first box.
- To find the percentage decrease between two numbers, enter the old and the new value in the second box.
- Results update as you type, with the working underneath.
How to reduce a number by a percentage
Multiply it by (1 − percentage ÷ 100). To reduce 250 by 20%: 250 × 0.8 = 200.
How to calculate a percentage decrease
Subtract the new value from the old value, divide by the old value and multiply by 100. From 120 to 90: (120 − 90) ÷ 120 × 100 = 25% decrease.
Going back up
A decrease and the same increase don't cancel out. After a 25% drop from 120 to 90, you need a 33.3% increase to get back to 120, because the increase is measured from the smaller number. This is why investments that fall by half need to double to recover.
Frequently asked questions
What's the difference between percentage decrease and percentage points?
If an interest rate falls from 5% to 4%, it dropped by 1 percentage point, which is a 20% decrease. Percentage points compare two percentages directly.
Is it free?
Yes, free with no sign-up. Everything is calculated in your browser.