The seven fundamental (base) dimensional units that make up the SI system are: | Notation | Dimension | Possible units | |----------|-----------|----------------| | T| seconds | seconds, days | |L|Length|nanometers, feet, lightyears| |M|Mass|Micrograms| |A|Population| Individual, Packs, Communities| |Θ|temperature| kelvin, degrees fahrenheit| |I|Electric Current| Ampere| See [[Derived Dimensions]]