# Definition:Dimension (Measurement)/Fundamental Dimensions

## Definition

The fundamental dimensions are:

Mass, denoted $M$ or $\mathbf M$
Length, denoted $L$ or $\mathbf L$
Time, denoted $T$ or $\mathbf T$

It is convenient at elementary levels of physics to add:

Temperature, denoted $\Theta$
Electric charge, denoted $Q$ or $\mathbf Q$

However, it is possible to define these in terms of mass, length and time, so strictly speaking they are not fundamental, as such.