The net speed achieved by an electron in a current carrying conductor is called as drift velocity. The average velocity acquired by the free electrons along the length of a metallic conductor under a potential difference applied across the conductor is called drift velocity of the electrons.
${\mathit{v}}_{\mathit{d}}=\frac{\mathit{I}}{\mathit{n}\mathit{e}\mathit{A}}$
Here:
I is the current flowing through the conductor. $\mathit{n}$ is the number density of an electron.
$\mathit{A}$ is the area of the conductor,
$\mathit{e}$ is the charge of the electron.