Percentage Calculator

A free online conversion calculator that calculate percentages, what if, increase/decrease easily. Get accurate results instantly without any software installation. Percentage calculations surface constantly: discount pricing during sales, tax rates on invoices, tip amounts at restaurants, grade scores in education, and margin analysis in business reports. Mental percentage math is notoriously error-prone, especially for percentage-change and percentage-of scenarios that trip up even numerate professionals. Three calculation modes cover 'X% of Y', 'X is what % of Y', and 'percentage increase/decrease from X to Y' — each updating instantly as you type the inputs. Choose a calculation mode — percentage of a number, what percent X is of Y, or percentage increase/decrease — enter your values, and the result appears immediately with the underlying formula shown for transparency. Multiple modes let you switch between discount math and growth-rate analysis without re-entering data. All percentage computations execute as client-side JavaScript arithmetic. Financial figures, salary data, and pricing models remain entirely within the browser session — no sensitive business metrics are ever transmitted or logged remotely.