Percentage Calculator

A free tool to calculate percentages with ease

Percentage Calculator is a lightweight, fast Chrome extension that helps users do common percentage math instantly from the toolbar. With a clean, modern interface and three focused calculation modes - "What is X% of Y?", "X is what percent of Y?", and "Percentage Increase/Decrease" - it removes friction when you need quick, accurate percentage results for shopping, budgeting, analytics, invoices, or studying. Three Modes: Choose between percentage-of, percentage-of-what, and percent change calculations with a single tap. Keyboard Friendly: Press Enter to calculate; fields validate input and give immediate feedback. Clear Results: Results are displayed with clear units and helpful formatting; values can be copied quickly. Responsive Design: Compact layout and animations make the popup pleasant to use on any screen size. Privacy-First: All calculations run locally in the extension; no data is transmitted or stored externally. Accessible & Usable: Clear labels, focus states, and accessible input handling improve usability for diverse users. Offline Ready: Works without network access because all logic runs in the popup. Examples: 10% of 10,000 = 1,000 100 is what percent of 800 = 12.5% From 2000 to 1000 = -50% (decrease) This extension is small, single-purpose, and designed to be intuitive: open the popup, enter numbers, and get an immediate result.