Percentage Calculator: Easy Percent Formulas and Examples
Percentages appear in discounts, taxes, grades, tips and growth figures. A Percentage Calculator gives the answer instantly, so you do not have to remember the formulas.
Five calculators in one
- Percent of a number: what is 20% of 150? The answer is 30.
- What percent is it?: 30 is what percent of 150? The answer is 20%.
- Percentage change: from 80 to 100 is an increase of 25%.
- Add or subtract a percent: add 15% to 200 to get 230, or subtract it to get 170.
- Find the total: 30 is 20% of 150.
The formulas
- Percent of a number: multiply the number by the percent, then divide by 100.
- What percent: divide the part by the whole and multiply by 100.
- Percentage change: subtract the old value from the new one, divide by the old value, then multiply by 100.
How to use the tool
- Find the calculator that matches your question.
- Type your two numbers into the boxes.
- Read the result, which appears as you type.
Everyday uses
- Shopping: work out the price after a 30% discount.
- Tax and tips: add or subtract a percent from a bill.
- School: turn a score into a percentage.
- Business: measure growth in sales, traffic or prices.
- Budgeting: see what share of your income goes on each cost.
Common mistakes
- A 50% increase followed by a 50% decrease does not return to the start. The decrease applies to a bigger number.
- A percentage point is not the same as a percent. Going from 10% to 12% is 2 percentage points, but a 20% increase.
- Always check which number is the starting value. Changing the order changes the answer.
Clear error messages
If a calculation is impossible, such as dividing by zero, the tool tells you why instead of showing a wrong number. Results are rounded to four decimal places.
A quick example
A jacket costs 120 and has a 25% discount. Use Add or subtract a percent with 25 and 120. The subtract result is 90, so you pay 90 and save 30. Check the same sale with Percent of a number: 25% of 120 is 30, which matches.
Free and private
The calculator runs in your browser. Your numbers are not stored or sent anywhere, and there is no sign up or login.
Frequently asked questions
How do I find a discount price? Use Add or subtract a percent and read the subtract result.
Can it handle decimals and negative numbers? Yes. Both work in every calculator.