How to use the percentage calculator
This percentage calculator answers three common questions: What is X% of Y? (find a part), X is what % of Y? (find the percent), and Y is X% of what? (find the whole). Select the type from the dropdown, enter the first number (X) and second number (Y), then click "Get result" or press Enter. The answer is shown with two decimal places. For "What is X% of Y?" the result is a number; for "X is what % of Y?" the result is a percentage. No sign-up required—it runs in your browser and works on phones and tablets.
Use it for sale prices (e.g. 20% off), tips (e.g. 15% of the bill), test scores (e.g. 18 out of 20 is what percent?), tax (e.g. 8% of total), or any situation where you need to switch between a part, a whole, and a percent. The formulas are: part = (percent / 100) × whole, and percent = (part / whole) × 100. The calculator applies the right formula based on the mode you choose and shows a short line explaining the result (e.g. "12 is 15% of 80") so you can verify at a glance.
The layout is responsive: the input card and result panel sit side by side on larger screens and stack on small screens for easy use on mobile. This page is optimized for search so you can find the percentage calculator quickly when you need it for homework, shopping, or quick checks.