Percentage Calculator
Find a percentage of a number, what percent one number is of another, or the percent change.
About this tool
Three of the most common percentage questions in one place: what is X percent of Y, X is what percent of Y, and by what percent did a value change. Type the numbers and every answer updates instantly, which makes it handy for discounts, tips, grades, taxes and growth figures.
How to use it
- Pick the box that matches your question.
- Type the two numbers.
- Read the answer beside the equals sign. It updates as you type.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For example, 20% of 150 is 0.20 × 150 = 30.
How is percentage change calculated?
Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase and a negative result is a decrease.
Why is percent change not symmetric?
Going from 100 to 150 is +50%, but going from 150 back to 100 is -33.3%, because each change is measured against a different starting value.