About the Unit Converter
What is this?
Unit conversion is the process of expressing the same quantity in different units of measurement — metres to feet, kilograms to pounds, litres to gallons. It is one of the most practical everyday maths skills, essential for cooking, travel, construction, and science. This converter handles length, weight, temperature, volume, and more.
How it is calculated
Most conversions use a fixed ratio called a conversion factor. To convert, multiply by the factor that cancels the original unit and introduces the target unit. For example, to convert 5 kilometres to metres, multiply by 1,000 (since 1 km = 1,000 m) to get 5,000 m. Temperature is the exception: Celsius, Fahrenheit, and Kelvin require formula-based conversions rather than simple multiplication.
Reference ranges
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply the Celsius temperature by 9/5 and add 32. For example, 20°C = (20 × 9/5) + 32 = 68°F. To convert back, subtract 32 and multiply by 5/9.
Why are there different measurement systems?
Historical reasons. The metric system was standardised during the French Revolution for consistency; the imperial system evolved from earlier English units. Most countries have now adopted metric officially.
How accurate are unit conversions?
Conversion factors are exact by definition for most units. The main source of error is rounding — for everyday use, three significant figures are usually more than enough.
Unit Converter
Convert between units across length, weight, volume, speed, area, and temperature.