# Magnitude

The magnitude tells us the size of the vector.

If $$\overrightarrow {PQ} = \left( {\begin{array}{*{20}{c}} a\\ b\\ c \end{array}} \right)$$ then the magnitude of $$\overrightarrow {PQ}$$ is written as $$\left| {\overrightarrow {PQ} } \right|$$ and is calculated by the formula below:

$\left| {\overrightarrow {PQ} } \right| = \sqrt {{a^2} + {b^2} + {c^2}}$