This free unit converter switches between common measurement units for length, weight, and temperature. For length you can convert millimetres, centimetres, metres, kilometres, inches, feet, yards, and miles. For weight it covers milligrams, grams, kilograms, tonnes, ounces, and pounds. For temperature it converts between Celsius, Fahrenheit, and Kelvin. Results update instantly as you type, entirely in your browser, with no sign-up and no cost.
It is built for a global audience, so whether you think in US customary units or metric, you can convert in either direction. This is useful for cooking, travel, school, fitness, shipping, and DIY projects.
How to use it
Choose a category, type a value, then pick the units to convert from and to. The conversion appears immediately, and you can swap units any time.
How the unit converter works
Each category has a base unit, and every other unit is defined as a ratio of it. To convert, the tool turns your value into the base unit and then into the target unit:
result = value × (factor of "from" ÷ factor of "to")
Temperatures use their own formulas (for example, °F = °C × 9/5 + 32).