Percentage Calculator

What is Percentage?

A percentage is a way to express a number as a fraction of 100. The word comes from the Latin “per centum,” meaning “by the hundred.” It is widely used in finance, statistics, science, and everyday calculations. Whether you are calculating a tip, determining a discount, measuring growth, or analyzing data, percentages provide a simple and standardized way to compare values and understand proportions.

For example, if 30 out of 200 students passed an exam, you can express this as 15%. This makes it easy to compare with other classes or exams regardless of the total number of students. Percentages are everywhere—interest rates, tax rates, exam scores, battery levels, weather forecasts, and more.

How to Calculate Percentages

There are three common percentage calculations you may need:

1. Finding X% of Y:Multiply Y by X/100. For example, 25% of 200 = (25/100) × 200 = 50. This is useful for calculating discounts, tips, or tax amounts.

2. Finding what percentage X is of Y:Divide X by Y and multiply by 100. For example, 50 is what percent of 200? (50/200) × 100 = 25%. This is useful for understanding proportions, such as what percentage of your budget is spent on rent.

3. Percentage change from X to Y:Subtract the old value from the new value, divide by the old value, and multiply by 100. For example, if a price went from $80 to $100, the change is ((100-80)/80) × 100 = 25% increase. This is commonly used in finance to track stock performance, revenue growth, or inflation.