About This Tool

This calculator handles the four most common percentage tasks people search for. Results update live as you type — no buttons to click, no page reloads. Click any result to copy it to your clipboard.

100% Client-Side

All calculations happen in your browser. No data is sent to any server. There is no backend, no database, and no logging.

Calculator Modes

• What is X% of Y? — Enter a percentage and a number to find the result (e.g., 15% of 200 = 30).
• X is what % of Y? — Enter a part and a whole to find the percentage (e.g., 30 is 15% of 200).
• Percentage change — Enter a starting value and ending value to find the percentage increase or decrease.
• Increase / decrease by % — Enter a value and a percentage to calculate the result after an increase or decrease.

Precision

Results are displayed with up to four decimal places and formatted with locale-aware number separators for readability.

Contact

Questions or feedback? Reach us at the feedback link in the navigation.