Percentage Calculator
Work out percentages, increases, decreases and what-of-what — three calculators in one.
20% of 150
30
What is the Percentage Calculator?
The Percentage Calculator answers the three most common percentage questions in separate modes: "What is X% of Y?", "A is what percent of B?" and "What is the percentage change from old to new?". Results update live as you type.
Calculations run in your browser, so real salaries, scores and budgets never leave your device.
How to use the Percentage Calculator
- 1Pick a mode from the tabs at the top.
- 2For "X% of Y", enter the percentage and the amount.
- 3For "A is what % of B", enter the partial value and the total.
- 4For "% change", enter the original and new values.
- 5The result appears below the inputs as soon as you finish typing.
Key features
- Three modes: percent-of, is-what-percent-of, percent-change
- Live recalculation on every keystroke
- Handles negative changes (decreases show as negative %)
- Works with any currency or unit
Frequently asked questions
How do I calculate a percentage increase?
Use "% change" mode: enter the original value first and the new value second. Positive means increase, negative means decrease.
How is the calculation done?
X% of Y: (X ÷ 100) × Y. A of B: (A ÷ B) × 100. Change: ((new − old) ÷ old) × 100.
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