Percentage Calculator
Calculate percentages, percentage change, and percentage of totals.
Result
How it works
The calculator applies the selected percentage formula and shows the computed value immediately.
FAQ
What is a percentage?
A percentage is a number expressed as a fraction of 100. The word comes from the Latin "per centum," meaning "per hundred." When you say 25%, you mean 25 out of every 100, or one quarter. Percentages make it easy to compare quantities of different sizes on a common scale.
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 20% of 150 = (20 × 150) ÷ 100 = 30. A quicker mental shortcut: move the decimal one place left to get 10% (150 → 15), then double it to get 20% (15 × 2 = 30). This tool calculates it instantly.
How do I calculate what percentage one number is of another?
Divide the part by the whole, then multiply by 100. For example, to find what percentage 45 is of 200: (45 ÷ 200) × 100 = 22.5%. This is useful for grading, survey results, and measuring progress toward a goal.