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Percentage calculator
Percent of, what percent, percent change.
Questions
What does this tool do?
The Percentage calculator answers the three percentage questions people run into. “X% of Y” finds a part of a whole — discounts, tips, tax. “X is what % of Y” turns two numbers into a share of the total. “Percent change from X to Y” measures growth or decline, and goes negative when the value drops. Pick the mode, type two numbers, and the answer updates as you type; each mode shows the arithmetic behind the result.
How is “% of” calculated?
X% of Y is (X ÷ 100) × Y. So 15% of 200 is 30 — discounts and tax estimates.
How is “what %” calculated?
X is what % of Y is (X ÷ Y) × 100. So 50 is 25% of 200 — a share of the total.
How is “% change” calculated?
The change from X to Y is ((Y − X) ÷ X) × 100. A negative result is a decrease — growth, price changes, savings.