Faraday's Law Calculator
Enter the known values and run the calculation.
Enter the turns count, the change in flux, the flux unit, the time interval, and the time unit.
Run the tool to calculate the induced EMF using the standard sign convention from Faraday's law.
Overview
Estimate induced EMF from changing magnetic flux for electromagnetics and induction scenarios.
Use this tool to estimate the induced voltage produced when magnetic flux changes through a coil over a stated interval.
Use it for induction examples, transformer intuition, and quick checks when you want the order of magnitude of the induced EMF before moving to geometry-specific modeling.
The math and how it's used
Flux is normalized into webers and time is normalized into seconds before the induced voltage is calculated.
The negative sign reflects Lenz's law convention for the induced polarity.
This is most useful for order-of-magnitude checks around coils, changing fields, and induced voltage before you get into geometry-specific magnetic modeling.
The sign follows the usual Lenz-law convention, but the actual polarity you see in hardware still depends on winding direction, reference orientation, and the way the flux is changing.
What to watch
The result assumes the stated flux change is representative of the full linked flux through the turns. Real field geometry, coupling, and waveform shape can change the observed voltage.
If polarity direction matters in hardware, confirm the winding orientation and reference direction instead of relying on sign convention alone.