How to use the magnetic flux converter
- Type the flux in Value.
- Pick the unit in From: webers, milliwebers, microwebers, nanowebers, maxwells or kilomaxwells.
- Pick the target unit in To.
- Read the result and the table of all six units. The swap button reverses the direction.
What it does and when to use it
Magnetic flux measures how much magnetic field threads through a surface, such as the core of a transformer or the face of a magnet. Modern engineering uses the weber and its prefixes. Many magnet datasheets, fluxmeters and older textbooks still use the CGS maxwell, sometimes called a “line”. This converter switches between the two systems without counting zeros by hand.
Typical uses: comparing a fluxmeter reading in maxwells with a design value in µWb, checking a transformer core calculation, or working through a physics problem that mixes CGS and SI. If your numbers are a flux density, turn them into flux first by multiplying by the area. The area converter helps when the area is in cm² or in². Coils link flux to current through inductance, which the inductance converter handles.
How it works
The weber is the base. Conversion is value × from-factor ÷ to-factor:
| Unit | Webers | Also written |
|---|---|---|
| milliweber | 0.001 | mWb |
| microweber | 0.000001 | µWb |
| nanoweber | 0.000000001 | nWb |
| maxwell | 0.00000001 | G·cm², “line” |
| kilomaxwell | 0.00001 | kMx, “kiloline” |
The maxwell factor follows from the definitions: 1 gauss = 10⁻⁴ T and 1 cm² = 10⁻⁴ m², so 1 G·cm² = 10⁻⁸ T·m² = 10⁻⁸ Wb exactly.
Worked examples
Definition check. 100,000,000 Mx = 1 weber.
SI to CGS. 1 mWb = 100,000 maxwells, or 100 kilomaxwells.
A small magnet. A fluxmeter reading of 2,500 Mx is 25 microwebers.
Limits and tips
- Only flux units are offered. Teslas, gauss, oersteds and ampere-turns measure different quantities and are not in this list.
- Sign matters in physics. Flux can be negative if the field points the other way through your surface; the converter keeps the sign.
- Results under 1e-9 of a unit show in scientific notation.
- For the voltage a changing flux induces, work out webers per second and read it as volts; the voltage converter then gives mV or µV.
Frequently asked questions
How many maxwells are in a weber?
Is magnetic flux the same as magnetic field strength?
How do I get flux from flux density?
What is a line of flux?
Why is the weber written as V·s?
Sources
- NIST Guide to the SI, Appendix B.8: Factors for units listed alphabetically — NIST, accessed 2026-10-08
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