Percentage Decrease Calculator
Find the percentage drop between two numbers, or take a percentage off a number.
Decrease = 200 − 150 = 5050 ÷ 200 × 100 = 25%
How to calculate a percentage decrease
- Subtract the new value from the original value to get the decrease.
- Divide by the original value.
- Multiply by 100.
From 200 down to 150: the decrease is 50, and 50 ÷ 200 × 100 = 25%.
Taking a percentage off
Subtract the percentage from 1 to get a multiplier: 15% off is × 0.85, 30% off is × 0.70. Then multiply once. 80 with 15% off is 80 × 0.85 = 68. Stacked discounts multiply rather than add: 20% off and then a further 10% off is × 0.8 × 0.9 = × 0.72, which is 28% off, not 30%.
Examples
| Question | Working | Answer |
|---|---|---|
| 200 → 150 | 50 ÷ 200 × 100 | 25% |
| Price 1,250 → 999 | 251 ÷ 1,250 × 100 | 20.08% |
| 80 with 15% off | 80 × 0.85 | 68 |
Finding the price before a discount
If you paid 60 after a 25% discount, the original price was 60 ÷ 0.75 = 80. Adding 25% back onto 60 gives 75, which is wrong because the discount was taken from the higher original price. The reverse percentage calculator handles this.
Frequently asked questions
What is the percentage decrease formula?
Percentage decrease = (original value − new value) ÷ original value × 100.
How do I take a percentage off a number?
Multiply it by (1 − percentage ÷ 100). Taking 15% off 80 is 80 × 0.85 = 68.
How do I work out the percentage discount on a price?
Divide the amount saved by the original price and multiply by 100. A price cut from 1,250 to 999 saves 251, and 251 ÷ 1,250 × 100 = 20.08%.
Can a percentage decrease be more than 100%?
Not for a positive quantity: a 100% decrease takes it to zero. Values beyond −100% only appear when a quantity crosses from positive to negative, such as profit turning into a loss.