Question 1

How do I calculate a percentage of a number?

Accepted Answer

Multiply the number by the percentage divided by 100. For example, 20% of 150 is 150 × 0.20 = 30.

Question 2

How do I find what percent one number is of another?

Accepted Answer

Divide the first by the second and multiply by 100. So 30 out of 150 is 30 ÷ 150 × 100 = 20%.

Question 3

How do I calculate percentage change?

Accepted Answer

Subtract the old value from the new, divide by the old value, and multiply by 100. A rise from 40 to 50 is a 25% increase.

Percentage Calculator