Percentage Calculator solves the three most common percentage questions: What is 15% of 200? What percent is 30 out of 120? And by how much did a value go up or down, in percent? It's useful for discounts, tips, tax, exam marks, salary raises, price changes and business growth figures.
Results update as you type, and each answer comes with the formula, so you can see how it was calculated and repeat it on paper if you need to.
How to use the Percentage Calculator tool
- Choose the calculator that matches your question.
- Enter the two numbers.
- Read the answer instantly, along with the formula used.
- Change any value to recalculate.
Features
- X% of Y, X as a percent of Y, and percentage change.
- Live results as you type.
- Formulas shown for every answer.
- Handles decimals and negative numbers.
- Free, private and works offline.
Tips for best results
A percentage increase followed by the same percentage decrease does not bring you back to the start: 100 + 10% = 110, and 110 − 10% = 99. For exam marks, use 'X is what percent of Y' with your marks and the total marks. For discounts, 'X% of Y' gives the amount saved, so subtract it from the price to get the sale price.
Compatibility and limits
The Percentage Calculator gives results instantly as you type and works on phones, tablets and computers. Results are rounded for display but calculated at full precision. The numbers you enter are not saved, so refreshing the page starts a new calculation. Results are estimates for general information, so for important medical, legal or financial decisions, please check with a qualified professional.
Privacy: your files never leave your device
All calculations happen in your browser. The numbers you enter, such as dates of birth, weights or loan amounts, are never sent to a server or stored.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For example, 15% of 200 = 0.15 × 200 = 30.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. 30 out of 120 = 30 ÷ 120 × 100 = 25%.
How is percentage increase calculated?
(New − Old) ÷ Old × 100. From 80 to 100 is a 25% increase.
What's the difference between percent and percentage points?
Going from 10% to 12% is a rise of 2 percentage points, but a 20% increase.
Is my data stored?
No. Calculations run in your browser.