How to calculate percentages
- Pick the calculator that matches your question.
- Type your numbers into the boxes.
- The answer appears instantly, with the formula shown underneath.
About the Percentage Calculator tool
Percentages are everywhere: discounts, tips, tax, exam scores, price rises and investment returns. This page has three calculators for the questions people ask most often, and shows the formula so you can check the math yourself.
100% free
No limits, no watermarks and no sign-up.
Private
Results are estimates for information only, not financial advice.
Fast
No uploading or waiting in a queue. Results in seconds.
Works everywhere
Windows, Mac, iPhone, Android and Chromebook.
Frequently asked questions
How do I calculate X% of a number?
Multiply the number by X and divide by 100. For example, 15% of 80 = 80 × 15 ÷ 100 = 12.
How do I calculate percentage change?
Subtract the old value from the new value, divide by the old value and multiply by 100. From 50 to 65 is (65 − 50) ÷ 50 × 100 = a 30% increase.
How do I work out a discount?
Find the discount amount with “What is X% of Y”, then subtract it from the price. 25% off $40 is $10 off, so you pay $30.
What percent is one number of another?
Divide the first number by the second and multiply by 100. 18 out of 24 is 18 ÷ 24 × 100 = 75%.