Common Measurement Units - Basic SI Units

Unit	Symbol	Definition
meter	m	The meter is the basic unit of length. The meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second. Note that this definition exactly fixes the speed of light in a vacuum at 299,792,458 meters per second.
kilogram	kg	The kilogram is the basic unit of mass. It is the mass of an international prototype in the form of a platinum-iridium cylinder kept at Sevres in France. The kilogram is the only one of the SI units which is still defined in relation to an artifact rather than to fundamental physical properties (and is also the only one with a prefix [kilo] already in place).
second	s	The second is the basic unit of time. It is the length of time taken for the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom. This definition refers to a cesium atom at rest at a temperature of 0 K.
ampere	A	The ampere is the basic unit of electric current. It is named after the French physicist Andre Ampere (1775-1836). One ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed one meter apart in vacuum, would produce between these conductors a force equal to 2·10-7 newton per meter of length.
kelvin	K	The kelvin is the basic unit of temperature. It is 1/273.16th of the thermodynamic temperature of the triple point of water (which is at 0.01 °C). Zero kelvin is absolute zero (when molecular motion stops). It is named after the Scottish mathematician and physicist William Thomson 1st Lord Kelvin (1824-1907).
mole	mol	The mole is the basic unit of substance. It is the amount of substance that contains as many elementary units as there are atoms in 0.012 kg of carbon-12. This quantity is known as Avogadro's number.
candela	cd	The candela is the basic unit of luminous intensity. It is the intensity of a source of light that emits monochromatic radiation of frequency 540·1012 Hz and that has a radiant intensity in that direction of 1/683 watts per steradian. One candela is equal to the black-body radiation emitted by 1/60 cm2 of platinum at its melting point.