Percentage Calculator

The three modes: "% of a number" finds a part — e.g. 15% of 200 is 30 (handy for tips, discounts, sales tax). "X is what % of Y" finds a proportion — e.g. 30 out of 150 is 20% (test scores, completion). "% change" finds an increase or decrease — e.g. from 80 to 100 is a 25% increase (price rises, growth). Everything updates as you type, runs in your browser, and is never uploaded.