Math & Numbers

These tools are for anyone who needs quick percentage or number answers: students checking work, shoppers comparing discounts, or anyone doing “X% of Y” or percent change in their head or on paper.

Common tasks include working out a tip, finding a sale price, comparing two values as a percent, or converting between number formats like Roman numerals. Everything runs in the browser—no sign-up or app.

Pick the percentage calculator when you need “percent of” or “what percent.” Use the discount calculator when you have an original price and a percent-off or amount-off. For number-format conversion, use the Roman numerals tool.