How to calculate percentages
A percentage is just a fraction out of 100. To find a percentage of a number, multiply the number by the percent and divide by 100. To find what percent one number is of another, divide the first by the second and multiply by 100. To find percentage change, take the difference between the new and old values, divide by the old value, and multiply by 100.
Everyday uses
Percentages show up everywhere: discounts while shopping, tips at restaurants, interest on savings, tax, exam scores, and price changes. Having a quick calculator saves time and avoids mistakes.
Frequently asked questions
What is 20% of 150?
150 × 20 ÷ 100 = 30.
How do I add a percentage to a number?
Find the percentage of the number, then add it to the original. For a 10% increase on 200: 200 + (200 × 10 ÷ 100) = 220.
Is my data saved?
No. Everything runs in your browser.