What this calculator does
Calculate percentage increase or decrease and show the change relationship.
How it works
The calculator evaluates percentage change = (new − original) ÷ |original| × 100%. Inputs are checked before calculation, and invalid values such as zero denominators or out-of-range selections produce a clear error instead of a misleading result.
Input query strings and outputs
Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.
Input query strings
2-
?originalValue=Original valueNumber · Required · Default: 80
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?newValue=New valueNumber · Required · Default: 100
Outputs
4-
percentageChangePercentage changePercentage · Primary output
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absoluteChangeAbsolute changeNumber
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changeTypeChange typeText
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multiplierNew/original multiplierNumber
Inputs and results
The inputs are Original value, New value. Results include Percentage change, Absolute change, Change type, New/original multiplier.