Percentage Calculator

How to calculate percentages

1. To find a percentage of a number, fill in the first calculator: 15% of 200 is 30.
2. To find what percent one number is of another, use the second: 30 is 15% of 200.
3. To find the percentage increase or decrease between two values, use the third.

Frequently asked questions

How do I work out a percentage by hand?

Divide the percentage by 100 and multiply: 15% of 200 = 0.15 × 200 = 30.

How is percentage change calculated?

Subtract the old value from the new one, divide by the old value and multiply by 100. From 200 to 250 is (250 − 200) ÷ 200 × 100 = 25%.

Why is a 50% drop not undone by a 50% rise?

Because the second percentage is of a smaller number. 100 falls 50% to 50, and a 50% rise from 50 only reaches 75.