百分比计算器

How to Use This Tool

1. 1

   Choose a calculation mode

   Select from three modes: find a percentage of a number, calculate percentage change between two values, or determine what percent one number is of another.

2. 2

   Enter your numbers

   Type the values into the input fields. The labels change depending on the selected mode to guide you.

3. 3

   View the result instantly

   The percentage result updates in real time as you type. No need to press a calculate button.

4. 4

   Copy to clipboard

   Click the result to copy it to your clipboard for use in spreadsheets, documents, or other applications.

Frequently Asked Questions

How do I calculate a percentage of a number?

Select the 'Percent Of' mode, enter the base number and the percentage value. For example, to find 20% of 150, enter 150 and 20. The calculator instantly shows 30.

What is percentage change and how is it calculated?

Percentage change measures the relative difference between an old value and a new value. The formula is ((New − Old) / |Old|) × 100. A positive result means an increase, and a negative result means a decrease.

Can I use decimal numbers?

Yes, you can enter decimal numbers in both input fields. The calculator handles decimals with up to 4 digits of precision in the result.

Is this percentage calculator free to use?

Absolutely. This online percentage calculator is 100% free, requires no sign-up, and works entirely in your browser with no data sent to any server.