Solenoid Inductance Calculator

About this calculator

This calculator finds the inductance of a solenoid (coil): L = μ0 · μr · N² · A / l, where μ0 is the permeability of free space, μr is the relative permeability of the core material, N is the number of turns, A is the cross-sectional area, and l is the coil's length. Inductance grows with the square of the turn count, so doubling the turns quadruples it, and a ferromagnetic core (high μr) can boost inductance dramatically over an air core.

Electronics engineers and hobbyists use it when winding custom coils or inductors for filters, transformers, chokes, and RF circuits, to predict how a design's turns, geometry, and core material will affect its inductance before building it. Enter the turns, area, length, and core permeability to get the inductance.