Calculating Percent Of
This is one of the most common percentage calculations: finding what a certain percentage of a number equals. It's used daily in shopping, taxes, tips, and business.
Formula
Result = (Percentage / 100) x Number
Simple Steps
- Convert the percentage to a decimal (divide by 100)
- Multiply by the number
- The result is your answer
Examples
Example 1: What is 20% of 150?
Result = (20 / 100) x 150 = 0.20 x 150 = 30
Example 2: Calculate 15% tip on a $60 bill
Tip = (15 / 100) x 60 = $9
Example 3: 8% sales tax on $250
Tax = (8 / 100) x 250 = $20
Common Applications
- Sales tax calculations
- Restaurant tips
- Discount amounts
- Interest calculations
- Commission rates
- Grade calculations
Quick Mental Math
For 10%, just move the decimal point left one place. For 5%, take half of 10%. For 1%, move decimal left two places.
Quick Tips
- Double-check your inputs for accurate results
- Use parentheses to clarify order of operations
- Results are rounded — consider significant figures
Frequently Asked Questions
Multiply Y by X/100.
25% of 80 is 20.
Move the decimal point one place to the left.
(Percentage / 100) x Number
Yes, if the percentage is greater than 100%.
Divide the number by 2.