Magnetism converters
Magnetomotive Force Converter
Convert magnetomotive force units: ampere-turns, gilberts and abampere-turns.
Result
0.795775 At
1 Gb = 0.795775 At
All units for this value
| Unit | Symbol | Value |
|---|---|---|
| Ampere-turn | At | 0.795775 |
| Kiloampere-turn | kAt | 0.000795775 |
| Milliampere-turn | mAt | 795.775 |
| Ampere | A | 0.795775 |
| Gilbert | Gb | 1 |
| Abampere-turn | abAt | 0.0795775 |
About this calculator
Magnetomotive force describes the magnetic equivalent of electromotive force, the driving influence that pushes magnetic flux through a coil, core, or magnetic circuit. This converter switches between the SI ampere-turn, the CGS gilbert, and the abampere-turn found in older electrical texts.
How it works in plain English
Magnetomotive force is generated whenever a current flows through one or more turns of wire, so its natural unit is the ampere-turn, equal to one ampere flowing through a single turn. The converter treats the ampere-turn as its common base, rescaling any entered value into that base before converting it into whichever target unit you choose, including kiloampere-turns and milliampere-turns for larger or smaller circuits.
The gilbert comes from the older CGS electromagnetic system and equals 10 divided by 4π ampere-turns, roughly 0.795775 ampere-turn, a factor that traces back to how the CGS system defines its magnetic units around a sphere rather than a straight wire path. The abampere-turn, another CGS-derived unit, equals ten ampere-turns, since the abampere itself is defined as ten amperes.
Choose your from and to units, type a value, and the converted magnetomotive force appears right away, with a table listing that same quantity across every supported unit at once. A precision control sets how many decimal places are shown, and a swap button reverses the two selected units instantly.
The formula
- value_in_target = value_in_source × (source factor to ampere-turn) ÷ (target factor to ampere-turn)
- 1 gilbert (Gb) = 10 ÷ (4π) = 0.795775 ampere-turn
- 1 abampere-turn = 10 ampere-turns
- 1 kiloampere-turn = 1000 ampere-turns
Worked example
Suppose a coil design specification lists a required magnetomotive force of 500 gilberts, a figure taken from an older CGS-based textbook, and an engineer needs that value in ampere-turns to match a modern coil-winding calculation. Multiplying by the gilbert factor: 500 × 0.795775 = 397.89 ampere-turns.
Entering 500 into the gilbert field with ampere-turn selected as the target shows about 397.89 ampere-turns immediately. Dividing that result back by 0.795775 returns 500, confirming the gilbert-to-ampere-turn scaling was applied correctly in that direction. The full unit table also reports this same figure as roughly 0.39789 kiloampere-turn and 39.789 abampere-turns, all computed from that single entered value without any extra lookup or manual multiplication, and scanning further down that same all-units table shows the equivalent reading in milliampere-turns for comparison against smaller coil designs.
Typical magnetomotive force values
| Example | Approximate magnetomotive force |
|---|---|
| Small relay coil | ≈50-200 ampere-turns |
| Electromagnet lifting small parts | ≈500-2000 ampere-turns |
| Transformer core (small) | ≈100-1000 ampere-turns |
| Large industrial electromagnet | ≈10,000+ ampere-turns |
| 1 gilbert | 0.795775 ampere-turn |
Standard unit definitions and general electromagnetics references
Frequently asked questions
What does magnetomotive force actually represent?
It represents the driving influence behind a magnetic field, analogous to how electromotive force drives current through a circuit. In a coil, it depends only on the current and the number of turns, not on the material the coil is wound around, which instead affects how much flux results from that driving force.
Why is the gilbert defined with a factor involving π?
The gilbert comes from the CGS electromagnetic unit system, which built its magnetic definitions around idealized spherical and radial geometries rather than the straight-wire loop used for the ampere-turn. That geometric difference is why converting between gilberts and ampere-turns involves a factor of 10 divided by 4π rather than a round number.
Is magnetomotive force the same as magnetic field strength?
No. Magnetomotive force is a property of an entire magnetic circuit or coil, similar to a total voltage, while magnetic field strength describes the intensity at a specific point in space, similar to a voltage gradient. Dividing magnetomotive force by a path length gives magnetic field strength.
Why would I need to convert ampere-turns to abampere-turns?
Abampere-turns appear in some historical CGS electrical engineering literature and specifications, so converting to or from them is mainly useful when comparing modern SI-based coil designs against older reference documents that used that unit convention.
Does the number of coil turns change the magnetomotive force unit used?
No, the unit stays the same regardless of turn count; ampere-turns simply combine current and turns into a single number. A coil with 10 turns carrying 2 amperes and a coil with 20 turns carrying 1 ampere both produce 20 ampere-turns of magnetomotive force.
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