About CalcuSwift

The fastest free unit converter on the web.

Our Mission: To make unit conversion and everyday calculations as fast and effortless as possible — for everyone, everywhere, for free.

What is CalcuSwift?

CalcuSwift is a free online unit converter and calculator website. We built it because we were frustrated with converter sites that are slow, cluttered with pop-ups, require sign-ups, or give inaccurate results. We wanted something clean, fast, and reliable — and so we built it.

Our site covers every major unit conversion category: length and distance, weight and mass, temperature, volume and liquid, area, speed, data storage, energy, pressure, time, and more. We also include practical everyday calculators for percentages, BMI, age, dates and square footage.

How It Works

CalcuSwift is a purely client-side website — all calculations happen in your browser using JavaScript. We don't send your data to any server, we don't store anything, and we don't require any personal information. It's just a fast, clean tool that works instantly on any device.

All conversion factors are based on the official International System of Units (SI) definitions and internationally recognised standards. We update our conversion data regularly to ensure accuracy.

Our Outdoor Weather Apps

CalcuSwift is part of a small family of free utility websites. Our sister sites include:

Contact Us

Have a suggestion for a new calculator or converter? Found an error? We'd love to hear from you. Visit our Contact page to get in touch.