Percentage Calculator
Three common percentage calculations in one place — percent of a number, what percent one number is of another, and percentage change.
% of=30
is what % of=25%
→=+25%
All three calculators update live as you type — no submit button needed.
Frequently Asked Questions
How do I calculate X% of Y?
Multiply Y by (X ÷ 100). For example, 20% of 150 is 150 × 0.20 = 30. The first calculator above does this instantly as you type.
How is percentage change calculated?
Percentage change = ((New Value − Old Value) ÷ |Old Value|) × 100. A positive result means an increase; negative means a decrease.
What's the difference between percentage change and percentage points?
Percentage change is relative (e.g., going from 50% to 60% is a 20% increase). Percentage points is the raw difference (10 percentage points) — this tool calculates percentage change, not points.
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