How a percentage decrease works
Multiply the starting value by 1 minus the percentage divided by 100. A 12% fall multiplies by 0.88.
The amount taken off is the starting value minus the new value.
Worked example
A value of 250 falls by 12%. The multiplier is 1 - 12 / 100 = 0.88, so the new value is 250 x 0.88 = 220.
The decrease is 250 - 220 = 30, which is 12% of 250.
Two falls in a row
Successive falls also multiply. A 12% fall then another 12% fall gives 0.88 x 0.88 = 0.7744, a 22.56% fall in total, not 24%.
This is why discounts applied one after another are not added together.
Inputs for the percentage decrease calculator
Starting value
The number before the fall. Negative values work too, and the decrease is measured on the size of the value.
Decrease by
The percentage taken off the starting value. Type 12 for a 12% fall.
CALCULATOR QUESTIONS
Percentage decrease calculator questions
How do I take 12% off a number?
Multiply by 0.88. For 250, the answer is 220 and the amount removed is 30.
Why is a 12% fall not undone by a 12% rise?
The two percentages apply to different bases. 250 falls to 220, then 12% of 220 is only 26.4, so the value returns to 246.4, not 250.
Can a percentage decrease be more than 100%?
Not in this calculator. A decrease of 100% takes the value to zero, and a larger fall would need a negative result, which the multiplier cannot produce from a positive start.
What is the multiplier for a 12% decrease?
0.88. Multiply any starting value by it to see the value after a 12% fall.