A physical quantity is quantity that can be measured and consist of numerical magnitude and a unit.

Physical Quantities can be classified into two types :

• The Base or Fundamental quantities
• The derived quantities

1. Base quantities
 table 1. Base quantities
Base quantities                         Name of unit                            Symbol for unit
  Length                                         meter                                            m
   mass                                        kilogram                                          kg
   time                                         second                                             s
Electric current                            ampere                                           A
temperature                                 kelvin                                             K
Amount of substance                   mole                                              Mol
Lominous intensity                      candela                                           cd





2. Derived quantities

• Derived quantities can be defined as quantities that can be derived out of the combination of the basic quantities 
• for instance a 'speed' is the ratio of a length by a time.
• An acceleration the ratio of a speed by a time, and 
• a force the multiplication of an acceleration by a mass

Physical quantity              Relation with base quantity             Symbol for unit

       Area                                           Length x width                                              m²

    Volume                                  Length x width x height                                  m³

    Speed                                         distance                                                          m·s⁻¹

                                                            ^time