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About UnitsConversion.io
UnitsConversion.io is a free online tool for converting between different units of measurement. Whether you need to convert kilometers to miles, kilograms to pounds, or Celsius to Fahrenheit, our converter handles it all instantly.
All calculations happen directly in your browser - we never send your data to a server. This means conversions are instant, private, and work even offline once the page has loaded.
We support both metric and imperial systems, plus specialized units used in science, engineering, cooking, and everyday life. From nanometers to nautical miles, from milligrams to metric tons - we've got you covered.
Frequently Asked Questions
Simply select a category (like Length or Weight), choose your "from" and "to" units, enter a value, and see the instant result. All calculations happen in your browser for maximum speed and privacy.
We support 13 categories including Length, Weight, Temperature, Volume, Area, Speed, Time, Data Storage, Energy, Pressure, Fuel Economy, Angle, and Frequency. Each category has multiple units from both metric and imperial systems.
Our conversions use precise mathematical formulas and conversion factors. Results are displayed with up to 6 significant digits for everyday use, with full precision available when copying to clipboard.
Yes! We support both metric (meters, kilograms, liters) and imperial (feet, pounds, gallons) units, plus many specialized units like nautical miles, stones, and BTU.
Yes, UnitsConversion.io is completely free. All conversions happen locally in your browser - we don't store your data or require any sign-up.