Percentage Decrease Calculator
Calculate the percentage decrease between two values, or reduce a number by a given percentage.
How to use this calculator
- Enter the starting (old) value.
- Enter the new, lower value.
- The result is shown as a positive 'decrease of X%'.
The formula
Decrease % = (Old − New) ÷ Old × 100- Old
- The starting value (cannot be zero)
- New
- The value after the change
How it works
The decrease is measured against the original value. Falling from 250 to 200 is a loss of 50 on a base of 250: 50 ÷ 250 = 0.20, a 20% decrease.
To apply a percentage decrease directly, multiply by (1 − p/100). Reducing 250 by 20% gives 250 × 0.80 = 200.
Worked example
A jacket drops from $89.99 to $67.49 in a sale.
- 1Change = 89.99 − 67.49 = 22.50
- 222.50 ÷ 89.99 ≈ 0.25
- 30.25 × 100 ≈ 25
The price decreased by about 25%.
When this calculator is useful
- Sale and clearance pricing
- Weight or consumption reduction
- Budget cuts
- Comparing performance drops
Frequently asked questions
How do I apply a 15% decrease to a price?
Multiply by 0.85 (which is 1 − 15/100).
Why is a 50% decrease not undone by a 50% increase?
The increase applies to the smaller new value. 200 − 50% = 100, but 100 + 50% = 150, not 200.