Length, weight, volume and temperature.
Converting between units of measurement is a daily necessity for millions of people — from cooks scaling recipes between metric and imperial, to engineers working across international standards, to travellers trying to understand distances and temperatures in unfamiliar countries.
This unit converter covers the most commonly needed conversions across four categories: length (millimetres to miles), weight (milligrams to stones), volume (millilitres to gallons) and temperature (Celsius, Fahrenheit and Kelvin). Conversion is instantaneous — results update as you type.
Select a category using the tabs at the top. Enter a value in the "From" field and select your source unit. Choose your target unit in the "To" field. The result appears instantly. Click the ⇅ swap button to reverse the conversion direction.
1 inch = 2.54 cm · 1 mile = 1.609 km · 1 pound = 0.453 kg · 1 US gallon = 3.785 litres · 0°C = 32°F · 100°C = 212°F. These are the most commonly needed conversions — use the tool for precise values and less common units.