Percentage Decrease Calculator: Measure a Drop Between Values
Calculate the percentage decrease from an original value to a lower one — how much something has fallen relative to where it began.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Percentage change | Difference |
|---|---|---|
| 200 to 150 | -25.00% | -50 |
| 100 to 75 | -25.00% | -25 |
| 1,500 to 1,200 | -20.00% | -300 |
| 60 to 9 | -85.00% | -51 |
How This Calculator Works
Enter the original value and the new, lower value. The calculator finds the drop between them, then divides by the original value to express the fall as a percentage. The result is shown as a negative change, confirming the direction of the move.
The Formula
Percentage Change
Old is the starting value, New is the ending value
Worked Example
A value falling from 200 to 150 has dropped by 50. Relative to the original 200, that is a 25% decrease. The same drop of 50 from a start of 100 would instead be a 50% decrease.
Key Insight
A percentage decrease can never exceed 100%, because a value cannot fall below zero. A 100% decrease means the value has disappeared entirely — there is nothing left to lose.
Frequently Asked Questions
How do I calculate a percentage decrease?
Subtract the new value from the original, divide by the original value, and multiply by 100. The result is the size of the drop as a percentage.
Can a percentage decrease be more than 100%?
No. A value cannot fall below zero, so the largest possible decrease is 100% — the point at which nothing remains.
Is a percentage decrease the opposite of an increase?
In direction, yes, but not in scale. A 50% decrease followed by a 50% increase does not return to the start, because each percentage applies to a different base.
What if the new value is higher?
Then there is no decrease — the result is a positive change, an increase. Use the percentage increase calculator for that case.
Does a discount work this way?
Yes. A price marked down from one figure to another is a percentage decrease, and this calculator measures exactly that drop.
Related Calculators
Data Sources & Benchmarks
This calculator draws on 1 independent, dated source.
Methodology & Review
Percentage decrease is the drop from the original value to the new value, divided by the original value. The result is reported as a negative change to confirm the direction.
Written by Ugo Candido · Last updated May 17, 2026.