Magnetic Flux Calculator

About this calculator

This calculator finds magnetic flux, Φ = B·A·cosθ, the measure of the total magnetic field passing through a surface, where B is the magnetic field strength, A is the surface area, and θ is the angle between the field lines and the surface's normal vector. Flux is maximum when the field is perpendicular to the surface (θ=0) and zero when the field runs parallel to it (θ=90°) — this quantity is the basis of Faraday's law of electromagnetic induction, since a changing flux is what induces an EMF.

Electrical engineering students use it to work through transformer, generator and inductor problems, and it's foundational for understanding how motors, generators and induction-based sensors work. Enter the magnetic field strength, area and angle to get the flux.