Percentage Calculator

How to Calculate a Percentage of a Number

Finding a percentage of a number is one of the most common math operations in everyday life. Whether you're figuring out how much a 25% discount saves you on a $200 jacket, calculating a 15% tip at a restaurant, or determining what 8% sales tax adds to your purchase — the underlying formula is always the same.

The Formula: Result = (Percentage ÷ 100) × Number

This works by first converting the percentage into its decimal equivalent. For instance, 25% becomes 0.25. Then you multiply that decimal by the number in question: 0.25 × 200 = 50. So 25% of 200 is 50.

Real-World Examples

• Shopping: A store advertises 30% off a $150 item. Enter 30 and 150 above — you save $45, paying only $105. For more on this, try our Discount Calculator.
• Tipping: Your dinner bill is $85 and you want to leave an 18% tip. That's $15.30. Our dedicated Tip Calculator can split this among diners too.
• Grades: You scored 42 out of 60 on a test. What percentage is that? Use our What Percentage Calculator to find it's 70%.
• Business: Your revenue grew from $80,000 to $100,000. That's a 25% increase — check it with the Percentage Increase Calculator.

Why Percentages Matter

Percentages provide a universal way to express proportions, making it easy to compare values of different scales. A 5% return on $1,000 and a 5% return on $100,000 represent the same rate of growth, even though the dollar amounts differ dramatically. This is why percentages are the language of finance, statistics, and science.

Want to deepen your understanding? Read our comprehensive guide on how to calculate percentages or start with the basics in What Is a Percentage?

Common Percentage Calculations

Each row links to the calculator with the numbers pre-filled — change them to fit your situation.