Percentage Calculator
About Percentage Calculator
What Is a Percentage?
A percentage is a way of expressing a number as a fraction of 100. The word itself comes from the Latin per centum meaning by the hundred. Percentages are everywhere in daily life: sales tax, tips, discounts, interest rates, grades, statistics, and probability all rely on percentages. Understanding how to calculate them quickly and accurately is an essential math skill. This calculator handles the three most common percentage operations people encounter: finding what percentage one number is of another, finding a percentage of a given number, and calculating percentage increase or decrease between two values.
Percentage Formulas
Three core formulas power this calculator. What is X% of Y? Answer = Y x (X/100). X is what percent of Y? Answer = (X/Y) x 100. Percentage change from X to Y: Change = ((Y-X)/X) x 100. A positive result indicates an increase while a negative result indicates a decrease. These three operations cover the vast majority of percentage questions people encounter in shopping, finance, academics, and data analysis.
How to Use This Calculator
Select the type of percentage calculation you need from the tabs. Enter your numbers in the appropriate fields and click Calculate. Results appear instantly. You can switch between calculation types without losing your previous inputs. The calculator handles decimals, large numbers, and negative values correctly, making it suitable for both simple everyday math and more complex statistical work.
Frequently Asked Questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 25% of 200 = 200 x 25 / 100 = 50. You can also move the decimal point two places left in the percentage and multiply directly.
What is percentage change?
Percentage change measures how much a value has increased or decreased relative to its original amount. The formula is ((New - Old) / Old) x 100. A price going from $80 to $100 is a 25% increase.
What is the difference between percentage and percentile?
A percentage is a fraction of 100. A percentile indicates the value below which a given percentage of observations fall. Being in the 90th percentile means you scored higher than 90% of the group.
