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Percentage Calculator

Three-in-one: "What is X% of Y?", "X is what percent of Y?", and "What is the % change from X to Y?"

What do you want to calculate?

First value (X)

Second value (Y)

Limitations: For percent change, X = 0 is undefined (can't compute percent change from zero). The tool flags this explicitly.

What to do next: Remember: a 50% increase followed by a 50% decrease does NOT return to the original — you end up at 75%.