Basic Dimensions


Distances can be specified in a variety of measures including miles, kilometers, feet, hands, etc.  In dimensional analysis one basic dimension, L, is used to describe distance.

By Rob Young from United Kingdom (Bluff Sign Post, New Zealand) [CC-BY-2.0], via Wikimedia Commons

There are six basic dimensions that be used to describe all engineering parameters. Writing parameters in terms of these basic dimensions is an important step in Dimensional Analysis.

All quantities used in engineering can be reduced to six basic dimensions.  These dimensions are 

         Mass M

         Length L

         Time t

         Temperature T

         Electric Current I

         Luminous Intensity J


All quantities used in fluid dynamics can be written in terms of the top four or M, L, t, T.