1. SI Base Units Table taken from: http://en.wikipedia.org/wiki/Internat ional_System_of_Units

2. SI base units Unit nameUnit symbolQuantity nameQuantity symbol Dimension symbol metremlengthl (a lowercase L), x, rL kilogramkilogram [note 1] [note 1] kgmassmM secondstimetT ampereAelectric currentI (an uppercase i)I kelvinK thermodynamic temperature TΘ candelacdluminous intensity I v (an uppercase i with lowercase non-italicized v subscript) J molemol amount of substance nN 1.Note^ Despite the prefix "kilo-", the kilogram is the base unit of mass. The kilogram, not the gram, is used in the definitions of derived units. Nonetheless, units of mass are named as if the gram were the base unit.^

3. What about the other units? All other units are “derived”. This means they come from some combination of the SI base units. Ex: volume comes from l x w x h – Could be measured in m or cm giving a unit of m 3 or cm 3 – Could also be a unit more common to liquid volumes of liters So, there is no “SI unit” for volume. There are derived units and one unit is not more correct than another. The preferred unit is related to the scale of what is being measured.

4. “What about units?” cont’d… You will sometimes hear in physics, “What is the SI unit for speed and velocity?” – It is really a derived unit of distance / time. – The SI unit for distance is meters. The SI unit for time is seconds. – So, the “SI unit” for speed and velocity is meters per second (m/s). See this page on Wikipedia for more examples.Wikipedia