Drift Velocity Calculator

An electric current is a movement of electric charges (usually electrons) in a wire. It may be a surprise, but these particles have a limited velocity. When you connect the electrical device to the socket, it immediately reacts. So how fast does electricity travel?

We have conducted some basic calculations of drift velocity for an electron in the text below if you want to learn more about it. We can already say that the current speed is relatively small, but there are a massive number of electrons that simultaneously feel an applied voltage. That's why our electrical device reacts so fast after connecting to a socket.

Our drift velocity calculator can be used for any charged particle and uses the below drift velocity formula:

where:

• uu – Drift velocity (average velocity of a particle);
• II – Current (you can compute it using our Ohm's law calculator);
• nn – Charge carrier number density;
• AA – Cross-sectional area of a wire; and
• qq – Charge on the charge carrier.

Our drift velocity calculator assumes that a current appears as a result of the flow of electrons with the elementary charge q=e=1.6×10−19 Cq=e=1.6×10−19 C.

Let's, for example, calculate the velocity of an electron in a thin copper wire (A=1 mm2)(A=1 mm2) with an electrical current I=10 AI=10 A. Copper is a conductor with a density of 8.94 g/cm38.94 g/cm3, an atomic weight of 63.546 g/mol63.546 g/mol, and one free electron per atom.

Using that data and our number density calculator you can estimate the charge carrier number density n=8.5×1028 electrons/m3n=8.5×1028 electrons/m3.

Finally, with our drift velocity calculator, we can compute that u=7.343×10−4 m/su=7.343×10−4 m/s, which is surprisingly slow!