Magnetic Flux Converter

Magnetic flux measures the total amount of magnetic field passing through a given surface — think of it as counting how many magnetic field lines pass through a loop of wire. When that count changes over time, it induces a voltage in the loop, which is the fundamental principle (Faraday's law) behind every generator, transformer, and inductor ever built.

Our Magnetic Flux converter supports the SI unit, weber (Wb), along with milliweber and microweber for smaller values, and volt-second, which is numerically and dimensionally identical to the weber (a direct consequence of Faraday's law: induced voltage equals the rate of change of flux, so flux itself works out to volts multiplied by seconds). The CGS unit, maxwell (Mx), along with kiloline, megaline, and line (older, largely synonymous terms for CGS flux units), and unit pole (the flux from a hypothetical isolated magnetic monopole) round out the historical unit options. Tesla-square-meter and tesla-square-centimeter express flux as flux density multiplied by area, and gauss-square-centimeter does the same in CGS units. The magnetic flux quantum is a fundamental physical constant — the smallest possible unit of magnetic flux that can pass through a superconducting loop, a cornerstone quantity in superconductivity and quantum physics.

To use the converter, select your starting and target units from the dropdown lists and enter a value — the result is calculated instantly to up to 12 significant digits. For example, converting 0.001 weber to maxwell gives exactly 100,000 Mx, a conversion frequently needed when comparing a modern transformer core's flux rating (in weber) against older CGS-based magnetics references.

Magnetic flux calculations are essential in transformer design (core flux must stay below saturation to avoid excessive losses and heating), generator and alternator design (the rate of change of flux linkage directly determines output voltage), inductor design (flux linkage relates to inductance and stored energy), and superconducting physics and quantum computing, where flux quantization plays a foundational role in devices like SQUIDs (superconducting quantum interference devices).

All conversion factors used in this tool are drawn from standard, internationally recognized unit definitions and precise physical constants, so results are dependable for electrical engineering, transformer and generator design, and physics research. The converter is free, requires no account, and works equally well on desktop and mobile devices.

Magnetic flux divided by area gives magnetic flux density, and magnetic flux divided by magnetic reluctance equals magnetomotive force — so this converter is often used alongside the Magnetic Flux Density and Magnetomotive Force converters elsewhere in this section when working through a complete magnetic circuit design from end to end.