Free Percentage Calculator
Three modes: X% of Y, X is what % of Y, and percentage change. 100% in your browser.
How It Works
Choose from multiple percentage operations: find X% of a number, calculate what percentage A is of B, or find the percentage change between two values. Enter your numbers, click Calculate, and get instant results with the formula shown. Everything runs in your browser with no data sent to any server.
When to Use It
- Calculating discounts, tips, or tax amounts during shopping or dining.
- Analyzing business metrics like profit margins, conversion rates, or year-over-year growth.
- Preparing financial reports that require percentage breakdowns of budgets, expenses, or revenue shares.
Frequently Asked Questions
How is percentage change calculated?
Percentage change = ((New - Old) / Old) x 100. A positive result means increase, negative means decrease. For example, going from 200 to 250 is a 25% increase: ((250-200)/200) x 100 = 25%.
Can I calculate reverse percentages?
Yes. Use the "X is what % of Y" mode. For example, to find what percentage 45 is of 180, enter 45 and 180 to get 25%. This is useful for calculating grade percentages, completion rates, and proportions.
Does it handle decimal percentages?
Yes. You can enter decimal values like 7.5% or 12.25%. Results are displayed with up to two decimal places for precision. This is essential for financial calculations where fractions of a percent matter.
All calculations happen in your browser. No data is sent to any server.