This magnetic flux converter changes total flux between webers, milliwebers, microwebers, maxwells and lines. The weber is the SI unit, equal to one volt-second. The CGS maxwell is exactly 10⁻⁸ Wb, and a line is the same as a maxwell, so 1 Wb = 100,000,000 Mx.
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How to use the magnetic flux converter
- Enter the flux, for example 2.5 mWb.
- In the magnetic flux converter, choose its unit and the target unit, such as Wb to Mx.
- Read the magnetic flux converter result: 2.5 mWb = 250,000 Mx.
For Wb to Mx, multiply by 100,000,000. For maxwell to weber, divide by 100,000,000. For µWb to Mx, multiply by 100.
What is magnetic flux?
Magnetic flux is the total magnetic field passing through an area, measured in webers (Wb). The CGS unit is the maxwell; 1 Wb = 10⁸ Mx.
Conversion formula
The magnetic flux converter stores every unit as a multiple of the base unit, the weber (Wb). To convert:
value in target unit = value × (factor of source unit ÷ factor of target unit)
where each factor is the size of the unit in webers.
Common magnetic flux conversions
| From | To | 1 unit equals |
|---|---|---|
| weber (Wb) | maxwell (Mx) | 100,000,000 Mx |
| maxwell (Mx) | weber (Wb) | 1 × 10−8 Wb |
| milliweber (mWb) | weber (Wb) | 0.001 Wb |
Magnetic flux converter worked example
Convert 25 webers to maxwells:
- Factor of Wb = 1 Wb
- Factor of Mx = 1 × 10−8 Wb
- 25 × 1 ÷ 1 × 10−8 = 2,500,000,000 Mx
Magnetic flux unit reference
| Unit | Symbol | Group | Equals (Wb) |
|---|---|---|---|
| Weber | Wb | SI | 1 |
| Milliweber | mWb | SI | 0.001 |
| Microweber | µWb | SI | 1 × 10−6 |
| Maxwell | Mx | CGS | 1 × 10−8 |
| Line (Maxwell) | line | CGS | 1 × 10−8 |
Reverse factors for each magnetic flux unit
The reference table gives each unit in webers. To go the other way, divide by that factor; the list below does the division for you.
- Milliweber (mWb), SI: 1 mWb = 0.001 Wb, so 1 Wb = 1,000 mWb.
- Microweber (µWb), SI: 1 µWb = 1 × 10−6 Wb, so 1 Wb = 1,000,000 µWb.
- Maxwell (Mx), CGS: 1 Mx = 1 × 10−8 Wb, so 1 Wb = 1 × 108 Mx.
- Line (Maxwell) (line), CGS: 1 line = 1 × 10−8 Wb, so 1 Wb = 1 × 108 line.
Flux from flux density and area
For a uniform field perpendicular to a surface, Φ = B × A. Convert B to tesla and A to square meters first:
| B | Area | Φ (Wb) | Φ (Mx) |
|---|---|---|---|
| 50 µT (Earth-scale) | 1 m² | 5 × 10⁻⁵ | 5,000 |
| 0.1 T | 10 cm² | 1 × 10⁻⁴ | 10,000 |
| 1.2 T | 25 cm² | 3 × 10⁻³ | 300,000 |
| 1.5 T | 100 cm² | 1.5 × 10⁻² | 1,500,000 |
In CGS, flux in maxwells is gauss times square centimeters.
A magnetic flux example: Faraday’s law
A changing flux induces a voltage: EMF = −N × ΔΦ ÷ Δt. As a magnetic flux example, a 100-turn coil whose flux falls from 3 mWb to 1 mWb in 0.01 s produces 100 × 0.002 ÷ 0.01 = 20 V. Because 1 Wb = 1 V·s, this unit check works directly. Use the magnetic flux density converter for B and the inductance converter, since L = NΦ ÷ I.
Flux in a transformer core
The peak flux in a transformer core follows Φ = V ÷ (4.44 × f × N). A 230 V, 50 Hz winding with 500 turns has a peak flux of about 0.00207 Wb, or 2.07 mWb. In the magnetic flux converter that is about 207,000 maxwells, since one weber is 10⁸ Mx.
Dividing by the core area gives the flux density. With a core area of 0.0015 m², B is about 1.38 T, a typical value for silicon steel. If the result is much higher, the core will saturate and draw large magnetizing currents.
The same formula explains why a 50 Hz transformer run on 60 Hz has less core flux, while running a 60 Hz design on 50 Hz raises the flux by about 20% and can push it into saturation. It is one reason equipment labels list the supply frequency next to the voltage.
Related converters and calculators
Related magnetic tools:
- Magnetic flux density converter: T and G
- Magnetic field strength converter: A/m and Oe
- Magnetomotive force converter: At and Gb
- Inductance converter: H, mH, µH
- Voltage converter: V and mV
Sources
BIPM: SI Brochure; NIST Special Publication 811, Appendix B.
Questions about this calculator
What is a weber?
The SI unit of magnetic flux, equal to 1 V·s or 1 T·m².
How many maxwells are in a weber?
100,000,000 Mx = 1 Wb exactly.
How do I convert maxwell to weber?
Divide by 100,000,000. For example, 50,000 Mx = 0.0005 Wb.
How do I calculate flux?
Φ = B × A. 0.5 T over 0.01 m² is 0.005 Wb.
What is a line of flux?
An old name for the maxwell: 1 line = 1 Mx = 10⁻⁸ Wb.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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