Percentage calculator
What is X% of Y, percent change, and “X is what % of Y”. Nothing is uploaded.
Ready
How it works
X% of Y = Y × (X/100). X is what % of Y = (X/Y)×100. Percent change from A to B = ((B−A)/A)×100.
Read each result row for its exact meaning. This is plain arithmetic, not finance advice.
Examples
25% of 200 = 50 50 is what % of 200 = 25% Change 80 → 100 = +25%
FAQ
Increase vs of? “20% of 50” is 10. “Increase 50 by 20%” is 60.
Negative change? If B is smaller than A, percent change is negative (a decrease).
Divide by zero? “What % of 0” is undefined — the tool reports an error.
Rounding? Results show up to 6 decimals when needed; copy the exact display.
Tax or APR? No — this is plain percentage arithmetic only.