Length Conversion Calculator
Inch definition. The inch (abbreviate as in or ") is a unit of length in Imperial the US metric system. The measure comes from - by some definitions - the width of a human thumb. In some languages, e. g. Norwegian, Afrikaans, Italian or French, an inch is derived from the word for thumb or, in some cases, its the same word. In the 14th century, the inch was defined by the king of England as . . .