Enter the magnetomotive force and the magnetic flux into the calculator to determine the magnetic reluctance.

Magnetic Reluctance Formula

The following equation is used to calculate the Magnetic Reluctance.

R = F / Φ
  • Where R is the magnetic reluctance (ampere-turns/weber)
  • F is the magnetomotive force (Ampere-turns)
  • Φ is the magnetic flux (Webers)

To calculate the magnetic reluctance, divide the magnetomotive force by the magnetic flux.

What is Magnetic Reluctance?


Magnetic reluctance is a magnetic property that describes the opposition to the magnetization of a ferromagnetic material when an externally applied magnetic field is increasing. This opposite reaction is called magnetostriction.

Treating the ferromagnet as an ideal paramagnet, magnetic reluctance may be derived from its response to an external magnetic field by setting up two opposing Lorentz forces.

The one due to magnetostriction balances the external field and leads to zero net flux, i.e., no change in magnetization, while the other due to magnetization leads to a non-zero net flux and thus causes magnetization.”

Reluctance is an essential factor in the design and use of transformers. In a transformer, the primary and secondary coils are wound so that their magnetic fields oppose one another; this phenomenon is called magnetic reluctance.

A transformer increases the voltage by decreasing the current through the coil’s resistance, converting some of it to heat and other electric energy losses. The greater the magnetic reluctance, the less current flows through the ring, and thus, the more voltage is produced per amp of input current.