Unit Converter
Convert length, weight, temperature, area, volume, speed, time and data units in one place.
What is it
A unit converter lets you move a measurement from one unit to another — meters to feet, kilograms to pounds, °C to °F. Under the hood each unit has a factor against a base unit, so converting is just multiplying and dividing. Temperature is the odd one out: it uses offsets, not just factors.
Notes & fun facts
Units are a museum of human history: the mile comes from 1000 Roman paces (“mille passus”), the nautical mile from one minute of latitude, and the US gallon still differs from the UK gallon (3.785 L vs 4.546 L). And a “byte” was originally a variable-sized chunk of bits — IBM standardized it to 8 bits in the 1950s, which is why KB is 1024 bytes, not 1000.
Origin & history
The metric system was born in revolutionary France: in 1799 the metre was defined as one ten-millionth of the distance from the North Pole to the Equator, and became the world’s reference. The SI system formalized it in 1960. Fahrenheit arrived in 1724, Celsius in 1742 (originally with boiling at 0° — Anders Celsius’s scale was inverted by Carl Linnaeus two years later). Nautical miles and knots survive from the age of sailing.