How the unit converter works
The converter uses a base-unit approach: all units in a category are first converted to a common base (metres for length, kilograms for weight, metres-per-second for speed), and then converted from that base to the target unit. Temperature uses direct formulas since it involves offsets rather than simple scale factors. All conversions run instantly in your browser with no server calls.
Length conversions
The length converter supports millimetres, centimetres, metres, kilometres, inches, feet, yards, and miles. These cover both the metric (SI) system used globally and the imperial system still common in the US, UK, and a few other countries. A kilometre equals exactly 1,000 metres; a mile equals 1,609.344 metres. Feet and inches are based on 0.3048 m per foot.
Weight and temperature
The weight converter covers milligrams through tonnes in metric, plus ounces and pounds in imperial. Temperature conversions use the standard formulae: °F = °C × 9/5 + 32, and K = °C + 273.15. Kelvin is the SI base unit of temperature and is used in science, while Celsius and Fahrenheit are used in everyday contexts in different parts of the world.
Speed conversions
Speed units include metres per second (SI base), kilometres per hour (most countries' road speeds), miles per hour (US and UK roads), and knots (nautical and aviation). One knot equals exactly one nautical mile per hour, or 1.852 km/h. Speed conversion is important for international travel, weather reports (wind speed), and reading foreign vehicle speedometers.