<P> The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived . The SI base units and their physical quantities are the metre for measurement of length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the candela for luminous intensity, and the mole for amount of substance . </P> <P> The SI base units form a set of mutually independent dimensions as required by dimensional analysis commonly employed in science and technology . </P>

The number of base units in si are