Percentage Calculator
How to Use
Select a calculation type, enter two values, and see the result instantly. Three modes are available: percentage of a number, what percentage one number is of another, and percentage change between two values.
What is Percentage Calculation?
A percentage expresses a number as a fraction of 100. Percentage calculations are among the most commonly used math operations in daily life, from calculating discounts and taxes to understanding statistics and financial returns. The word 'percent' comes from the Latin 'per centum,' meaning 'by the hundred.' This tool supports three essential percentage operations, making it easy to solve the most frequent percentage questions without a formula.
Formulas
X% of Y = (X / 100) × Y. X is what % of Y = (X / Y) × 100. % change = ((New − Old) / |Old|) × 100.
Common Use Cases
- Shopping discounts — calculate the final price after a percentage discount
- Tax calculation — determine tax amounts based on percentage rates
- Grade calculation — convert scores to percentages for academic grading
- Statistics — express proportions and ratios as percentages for easier comparison
- Investment returns — calculate percentage gains or losses on investments
Tips
When calculating percentage change, the direction matters — a 50% increase followed by a 50% decrease does not return to the original value. For example, 100 increased by 50% is 150, but 150 decreased by 50% is 75. To reverse a percentage increase of X%, the required decrease is X / (1 + X/100) × 100%. Keep this asymmetry in mind when working with financial data or comparing growth rates.
Privacy
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