Lorentz Force Calculator

About this calculator

The Lorentz force law describes the total electromagnetic force on a charged particle: F = qE + qv×B, which for a velocity at angle θ to the magnetic field reduces to a magnitude of F = qE + qvB·sin(θ). The electric-field term always acts along the field direction, while the magnetic-field term acts perpendicular to both the particle's velocity and the field — which is why it curves a moving charge's path instead of speeding it up or down.

This single equation underlies how charged particles behave in everything from a CRT electron beam to a mass spectrometer to the magnetic confinement in a tokamak. Physics students, electrical engineers, and plasma and accelerator physicists use it to size deflection fields, predict particle trajectories, and design components like velocity selectors and magnetic lenses.