Percentage Calculator

How to use this percentage calculator

Select the type of calculation you need, enter your numbers, and get the result instantly.

What is X% of Y?

Find a percentage of a number. Example: what is 20% of 150? Answer: 30. Useful for tips, discounts, commissions, and tax calculations.

X is what % of Y?

Find what percentage one number represents of another. Example: 30 is what % of 150? Answer: 20%. Useful for scores, progress tracking, and data analysis.

Percentage increase/decrease from X to Y

Calculate the percent change between two values. Example: price goes from 100 to 150. Answer: 50% increase. Useful for price changes, growth rates, and performance metrics.

Percentage difference between X and Y

Calculate the relative difference between two numbers as a percentage of their average. Example: 100 vs 150. Answer: 40% difference. Useful for comparing two values when neither is the "reference".

Common uses

• Shopping: Calculate sale prices and discount amounts
• Finance: Track investment returns and expense ratios
• Academics: Calculate test scores and grade percentages
• Business: Measure growth rates and market shares
• Health: Track body fat, macros, and nutrient percentages

Privacy note

This is a fully offline tool. All calculations run in your browser using plain JavaScript. Your numbers never leave your device. No signup, no tracking beyond anonymous usage counts, and no server-side processing.