Percentage Calculator

Common Ways People Use Percentage Calculator

The Percentage Calculator covers the four most common percentage questions people search for: finding what X% of a number is, working out what percentage…

• Working out what percentage one number is of another for a report.
• Calculating a percentage increase or decrease between two values.
• Figuring out a grade, discount, or commission percentage quickly.
• Checking percentage-based statistics before including them in a presentation.

Because Percentage Calculator runs entirely in your browser, none of the files or numbers you enter are uploaded anywhere — everything is processed locally on your own device and cleared as soon as you close the tab.

Percentage Calculations Explained

Finding a Percentage of a Number

To find X% of a number, multiply the number by X and divide by 100. For example, 25% of 200 is (200 × 25) / 100 = 50.

Percentage Increase or Decrease

To find the percentage change between two numbers, subtract the old value from the new one, divide by the old value, then multiply by 100.

Percentage of a Total

To find what percentage one number is of another, divide the part by the whole and multiply by 100.

Common Uses

Percentages show up everywhere — grades, discounts, statistics, tax rates, tips, and interest — which is why a quick calculator saves so much manual math.

More Things to Know

Percentage Points vs. Percentages

A change from 10% to 15% is a 5 percentage point increase, but a 50% relative increase — a distinction that matters a lot in statistics and finance.

Percentages in Grading

Teachers and students commonly use percentage calculations to convert raw scores into grades, making this one of the most frequent everyday uses of percentages.

Percentages in Finance

Interest rates, investment returns, and inflation are all expressed as percentages, making percentage literacy useful well beyond the classroom.

Common Mistakes

A common error is confusing 'percent of' with 'percent increase/decrease' — this calculator clearly separates the two so you get the right answer every time.

Additional Context

Percentages in Business Reporting

Growth rates, market share, and profit margins are almost always expressed as percentages, making percentage calculations a daily task in business analysis.

Reverse Percentage Problems

Sometimes you know the final amount after a percentage change and need to find the original number — this is a common but trickier percentage calculation.