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Find the percentage increase or decrease between an old and a new value.
How the calculation works
The calculator divides the change by the old value. A positive result is an increase and a negative result is a decrease.
Formula used
% change = (New − Old) ÷ |Old| × 100
Example
Going from 80 to 100 is a 25% increase.
Frequently asked questions
Why can’t the old value be zero?
Division by zero is undefined, so percent change cannot be calculated.
Is the reverse change the same?
No. Going from 100 back to 80 is a 20% decrease.
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Results are estimates for general information only and are not professional financial, medical or legal advice.