Faraday's Law of Induction Calculator
Induced EMF from a changing magnetic flux, and the peak/RMS EMF of a coil rotating in a magnetic field (AC generator).
How to use the Faraday's Law of Induction Calculator
- Enter or select: Number of turns N, Magnetic field B, Coil area A, Angle between B and coil normal, Time for flux to fall to zero Δt.
- Fill in what you know of: Rotation frequency (generator) — leave the unknown empty.
- The results (Magnetic flux Φ, Average induced EMF, Generator peak EMF, Generator RMS EMF) are calculated instantly as you type.
- Use “Copy link” to share the calculation with the same input values.
Formula
- ε = −N dΦ/dt (Maxwell–Faraday: ∇×E = −∂B/∂t)
- Φ = B·A·cosθ
- ε_peak = N B A ω
About this tool
The minus sign (Lenz's law) means the induced current opposes the change in flux. Values shown are magnitudes.