How to use the electron drift velocity calculator
Compute drift velocity of electrons in a wire. Enter current, wire diameter, carrier density in the fields above; the drift velocity is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- I — Current (A)
- d — Wire diameter (mm)
- n — Carrier density (10²⁸/m³)
Worked example
With current = 10 A, wire diameter = 2 mm, carrier density = 8.5 10²⁸/m³, the calculator gives drift velocity ≈ 0.2337334 mm/s.
Frequently asked questions
What is the formula for the electron drift velocity calculation?
Drift velocity (mm/s) = I / (n × 1e28 × π × (d / 2000)^2 × QE) × 1000. Here I is current (A), d is wire diameter (mm), n is carrier density (10²⁸/m³).
What inputs do I need for the electron drift velocity calculator?
You need current in A, wire diameter in mm, carrier density in 10²⁸/m³. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.