Unit Converter is a free online tool that instantly converts between hundreds of units across 15+ categories including Length, Weight, Temperature, Area, Volume, Speed, Time, Energy, Pressure, Power, Data Storage, Frequency, Fuel Efficiency, Angle and Cooking. Everything is calculated instantly in your browser — no data is sent to any server.

How to use: Select a category, enter a value in any field, and all other units update instantly. Switch categories using the tabs at the top.