Unit is a a standard measure that is used to express amounts, defined or adopted by tradition or law. e.g. millimeter, centimeter, meter or kilometer is a unit of length. Currently, the global standard of measurement is the International System of Units (SI). It is a modern form of the metric system. Unitconverted.com is a free unit converter that converts units based on International System of Units. The results generated by the unit converter are scientific, i.e. they are not rounded.