How it works

Each unit is defined by its exact relationship to a base unit (the meter for length, the kilogram for weight, and so on). Your value is converted to the base unit and then to the target unit, using internationally agreed-upon definitions like 1 inch = 25.4 mm exactly. Temperature is handled with dedicated formulas since Celsius, Fahrenheit, and Kelvin scales have different zero points. All calculations happen entirely in your browser -- nothing is sent to any server.