Free Online Percentage Calculator
Calculate percentages quickly and accurately with our free online tool. Whether you need to find what percentage one number is of another, or calculate a specific percentage of a number, we've got you covered.
How to Use
Mode 1: Enter a percentage (e.g., 20) and a number (e.g., 150) to find out what 20% of 150 is.
Mode 2: Enter a part number and a total number to find out what percentage the part is of the total.
Results are displayed with two decimal precision for accuracy.
Common Percentage Calculations
- Discounts: Calculate sale prices (e.g., 25% off $80)
- Tips: Determine tip amounts at restaurants
- Grades: Convert test scores to percentages
- Statistics: Find what percentage a value represents
- Growth: Calculate percentage increase or decrease
Formula Reference
Find percentage of a number:
Result = (Percentage / 100) x Number
Example: 15% of 200 = (15 / 100) x 200 = 30
Find what percentage one number is of another:
Result = (Part / Total) x 100
Example: 25 is what % of 200 = (25 / 200) x 100 = 12.5%
Why Use This Tool?
No more mental math or figuring out which formula to use. Our dual-mode calculator handles both common percentage scenarios instantly. All calculations happen locally in your browser - fast, private, and accurate.
Common Mistakes
A percentage point change is not the same as a percent change. Moving from 5% to 6% is a 1 percentage point increase, but it is a 20% relative increase because 1 is 20% of 5. For finance, grades, statistics, and analytics, check which meaning is intended before reporting the number.
Quick Answer
To find a percentage of a number, multiply the number by the percentage divided by 100. To find what percentage one number is of another, divide the part by the total and multiply by 100.
Last reviewed: July 2026.