Percentage Calculator
Work out percentages, percentage change and what-percent-of in one place.
Calculators
NUMBERS → %
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Percentages come up constantly — tips, discounts, grades, growth. This calculator handles the three questions people actually ask: what is X% of a number, X is what percent of Y, and what is the percentage change from one value to another. Type the numbers and the answer updates instantly.
How to calculate percentages
- Pick the calculation you need from the three modes.
- Enter your two numbers.
- Read the answer, calculated live.
- Switch modes to solve a related question without retyping.
The three calculations
| Question | Example | Result |
|---|---|---|
| What is 20% of 150? | 0.20 × 150 | 30 |
| 30 is what % of 150? | 30 ÷ 150 × 100 | 20% |
| Change from 150 to 180? | (180−150)/150 × 100 | +20% |
Calculator features
- Three modes: percent-of, what-percent and percentage change.
- Handles increases and decreases with a clear + or − sign.
- Live results as you type.
- Runs in your browser with no rounding surprises.
Frequently asked questions
How do I calculate a discount?
Use “what is X% of Y” to find the discount amount, then subtract it from the original price.
What is percentage change?
It measures how much a value grew or shrank relative to its starting point: (new − old) ÷ old × 100.
Why can a decrease never exceed 100%?
A value can only drop to zero, which is a 100% decrease. Increases, however, can exceed 100%.