Education
Percent Decrease Calculator
Enter the original value and the new value. The calculator returns the decrease amount, the percent decrease, and the multiplier needed to go from one to the other. If the new value is greater, it reports a percent increase instead.
e.g. 200
The smaller value if a decrease, the larger value if an increase. · e.g. 150
Decrease vs increase
Percent change is always expressed against the original (the denominator). A move from 200 down to 150 is a 25% decrease. A move from 150 up to 200 is a 33.33% increase. The same dollar change, but different percent because the starting points differ.
If the new value is greater than the original, the calculator reports the change as a percent increase instead.
Percent decrease
25%
From 200 down to 150.
Percent decrease = (original − new) / original × 100. If the result is negative, the new value is larger and the change is a percent increase. The multiplier shows what to multiply the original by to get the new value: 0.75 means a 25% decrease; 1.10 means a 10% increase.
Examples
200 → 150
Decrease 50 · 25%
120 → 90
Decrease 30 · 25%
$500 → $325
Decrease $175 · 35%
60 → 45.5
Decrease 14.5 · 24.17%
How it works
Percent decrease compares two values using the original as the reference. The formula divides the drop by the original and multiplies by 100 to get a percent.
Decrease · original − new
Percent decrease · (original − new) / original × 100
Multiplier · new / original
If the multiplier is less than 1, the change is a decrease. If it is greater than 1, the change is an increase.
Related calculators
- Percentage increase calculator for the opposite direction.
- Percentage calculator for the general "what is X% of Y" math.
- Percent error calculator for experimental-vs-theoretical comparisons.
- Discount calculator for retail-pricing percent reductions.
- All education calculators.
Frequently asked questions
Percent decrease = (original − new) / original × 100. Subtract the new value from the original, divide by the original, and multiply by 100. The result is the percent of the original that was removed.
Percent change is signed: positive for increases, negative for decreases. Percent decrease is always the positive magnitude of a decrease. If the new value is bigger than the original, percent decrease does not apply and the calculator labels the result as a percent increase instead.
Because percent is always taken against the starting value (the denominator). Going from 200 to 100 is a 100-point decrease on an original of 200, which is 50%. Going from 100 to 200 is a 100-point increase on an original of 100, which is 100%. Same dollar move, different percentages.
The multiplier is new / original. It is the number you multiply the original by to get the new value. A multiplier of 0.75 means a 25% decrease (75% of original remains). A multiplier of 1.10 means a 10% increase.
No. Percent change is not defined when the original is zero, because the formula divides by it. The calculator returns an error and asks for a non-zero original.
Only if the new value is negative. If both values are non-negative, the maximum percent decrease is 100% (everything is removed). A new value below zero means the quantity went past zero and into the negative.
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