Percentage Change Calculator — Three Modes
Result
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Formula
How to Calculate Percentages
Three modes: X% of Y = (X/100)*Y. X is what % of Y = (X/Y)*100. % Change = ((New-Old)/|Old|)*100. A positive result means increase; negative means decrease.
Percentage change is not symmetric: 50% increase from 100 gives 150, but 50% decrease from 150 gives 75, not 100. The base changes each time.
These calculations are used for tips, discounts, taxes, investment returns, grade calculations, and many everyday applications.
Frequently Asked Questions
How to calculate percentage change?
((New-Old)/|Old|)*100. From 80 to 100: ((100-80)/80)*100 = 25% increase.
Why is % change not symmetric?
50% up from 100=150. 50% down from 150=75, not 100. Base changes.
What % is X of Y?
(X/Y)*100. E.g. 30 of 120 = 25%.
How to find X% of a number?
Multiply by X/100. 15% of 80 = 12.