How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 15% of 200 is 200 × 15 ÷ 100 = 30.

How do I calculate percentage increase?

Subtract the old value from the new one, divide by the old value, then multiply by 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = 25%.

Divide the part by the whole and multiply by 100. 30 out of 200 is 30 ÷ 200 × 100 = 15%.

Percentage calculator

Three calculators in one: percent of a number, what percent X is of Y, and percentage change.

What is X% of Y?

Percent%Of

Result

X is what percent of Y?

Result

15%

Percentage increase or decrease

FromTo

Increase

25%

20 difference

Step 1
Pick the question
Use the box that matches what you want to know: X% of Y, X is what % of Y, or increase/decrease.
Step 2
Type the numbers
Enter your two values. The answer updates as you type.
Step 3
Read the result
Copy the answer. Nothing is sent anywhere.