What is X% of Y?

Find out what a percentage of any number comes to

What isof?

How it works

This is the most common percentage calculation: finding what a share of a total comes to. Use it for tips, commission, simple interest, a slice of a budget, or how much a sale saves you.

Result = (percentage ÷ 100) × value

Example: 15% of 200 is (15 ÷ 100) × 200 = 30. On a $200 sale with 15% commission, the commission is $30.

Step-by-Step:

  1. Start with the percentage: 15%
  2. Convert to decimal by dividing by 100: 15 ÷ 100 = 0.15
  3. Multiply by the value: 0.15 × 200 = 30

To find 15% of 200, we convert the percentage to a decimal and multiply. Think of it as "parts per hundred" - 15 out of every 100, applied to 200.

Frequently asked questions

How do you work out 10% of a number in your head?

Divide by 10: 10% of 250 is 25. From there 5% is half of that (12.50) and 20% is double (50).

How do you calculate 15% of a number?

Add 10% and 5% together. For 15% of 80: 10% is 8, 5% is 4, so 15% is 12. By formula: (15 ÷ 100) × 80 = 12.

What is the difference between a percentage of a number and a percentage increase?

A percentage of a number gives you just the share (15% of 200 = 30). A percentage increase gives you the new total (200 increased by 15% = 230).