Drift Velocity Calculator: Electron Flow in Cond...
Calculate the drift velocity of electrons in a conductor. Understand why electrons move slowly despite current being fast, and explore Ohm's Law at the microscopic level.
What is Drift Velocity?
Drift velocity is the average velocity of electrons flowing through a conductor under the influence of an electric field. Despite current flowing at nearly the speed of light in wires (due to the EM field), individual electrons move surprisingly slowly — typically just millimeters per second.
⚡ Drift Velocity Calculator
Use our free calculator for instant, accurate results.
📐 Formula
v_d = I / (n × A × q)
I = current (A), n = charge carrier density (m⁻³), A = cross-sectional area (m²), q = electron charge (1.6×10⁻¹⁹ C).
📝 Worked Example
Copper wire: I = 1A, diameter = 1mm (A = 7.85×10⁻⁷ m²), n = 8.5×10²⁸ m⁻³:
v_d = 1 / (8.5×10²⁸ × 7.85×10⁻⁷ × 1.6×10⁻¹⁹)
v_d ≈ 9.4×10⁻⁵ m/s = 0.094 mm/s
📝 How to Use the Calculator
❓ FAQ
If electrons move so slowly, why does current flow instantly?
When you flip a switch, the electric field propagates at nearly the speed of light throughout the circuit, pushing all electrons simultaneously — like water already in a pipe.
What is charge carrier density?
It is the number of free electrons per unit volume. For copper, n ≈ 8.5×10²⁸ electrons/m³.
Veer Kumavat
Founder & AuthorVeer is a 14-year-old student from Nashik, Maharashtra, who built SciFi Calculators to help students worldwide master STEM subjects. He is passionate about making complex science and math problems accessible through intuitive digital tools.