How to use the Percentage Calculator
- Pick the type of question you have.
- Enter the two numbers.
- Read the answer and the formula used to get it.
About this tool
Percentages come up everywhere: discounts, exam marks, salary raises, tax and growth figures. The three calculators here cover the questions people ask most, and each one shows the working so you can check it or use it again later.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 2,000 is 2,000 × 15 ÷ 100 = 300.
How is percentage change calculated?
Subtract the old value from the new value, divide by the old value, then multiply by 100. A positive result is an increase; a negative result is a decrease.
Why is a 50% drop not undone by a 50% rise?
Because each percentage is taken from a different starting value. 100 down 50% is 50; 50 up 50% is only 75.