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.
vd=‌

I

neA

Here:
I is the current flowing through the conductor. n is the number density of an electron.
A is the area of the conductor,
e is the charge of the electron.