Convert Ampere Turns to Gilberts
Ampere Turn (At) to Gilbert (Gi) magnetomotive force conversion — enter any value below to get an instant result, or use the table for common values.
Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.
Result
1 At = 1.2566371 Gi
1 Ampere Turn = 1.2566371 Gilberts
1 Gilbert = 0.79577472 Ampere Turns
1 At in every supported unit
Conversion chart: Ampere Turn to Gilberts
Conversion table
| Ampere Turn (At) | Gilbert (Gi) |
|---|---|
| 0.01 At | 0.012566371 Gi |
| 0.1 At | 0.12566371 Gi |
| 1 At | 1.2566371 Gi |
| 2 At | 2.5132741 Gi |
| 3 At | 3.7699112 Gi |
| 5 At | 6.2831853 Gi |
| 10 At | 12.566371 Gi |
| 20 At | 25.132741 Gi |
| 50 At | 62.831853 Gi |
| 100 At | 125.66371 Gi |
| 1000 At | 1256.6371 Gi |
Ampere Turn (At)
Definition: The SI-derived unit of magnetomotive force, equal to the MMF produced by a current of one ampere flowing through a single turn of a coil. A coil of N turns carrying I amps produces N×I ampere-turns of MMF.
History: It emerged directly from Ampère's law once the ampere became the SI base unit for current — since MMF is fundamentally current multiplied by number of turns, "ampere-turn" simply names that product rather than requiring a new physical constant.
Current use: The standard practical unit for designing transformers, motors, solenoids, and electromagnets — engineers compute how many turns of wire at how many amps are needed to reach a target magnetic field.
Gilbert (Gi)
Definition: The CGS-EMU unit of magnetomotive force, defined so that a magnetic circuit obeying Rowland's law (the magnetic analog of Ohm's law) with 1 gilbert of MMF driving against 1 unit of magnetic reluctance produces exactly 1 maxwell of flux. One gilbert equals 10/(4π) ≈ 0.7958 ampere-turns.
History: Named after William Gilbert, court physician to Queen Elizabeth I and author of the 1600 treatise De Magnete — widely regarded as the work that founded the scientific study of magnetism, centuries before the CGS unit system that eventually bore his name.
Current use: Still encountered in older magnetic-circuit textbooks and some permanent-magnet industry literature that continues to use CGS-Gaussian units for magnetic circuit calculations.
Supported Units
| Unit | Symbol | In Ampere-Turn |
|---|---|---|
| Kiloampere Turn | kAt | 1000 At |
| Ampere Turn | At | 1 At |
| Milliampere Turn | mAt | 0.001 At |
| Abampere Turn | abAt | 10 At |
| Gilbert | Gi | 0.79577472 At |
About These Parameters
- Value
- The amount of magnetomotive force you want to convert, expressed in the "From" unit. Accepts decimals, and can represent anything from a small relay coil's milliampere-turns to a large electromagnet's kiloampere-turns.
- From Unit
- The unit your input value is currently measured in — a coil design's ampere-turn figure, a transformer spec's kiloampere-turns, or an older magnetic-circuit text's gilbert value.
- To Unit
- The unit you want the result converted into. Use the swap button to flip From and To instantly, which is handy when translating a historical CGS-system gilbert figure into the modern ampere-turn or vice versa.
How Magnetomotive Force Conversion Works
The Formula
Every unit here is defined by a fixed multiplier relative to the ampere-turn. To convert a value from one unit to another:
result = value × (factor of "From" unit ÷ factor of "To" unit)
For Ampere Turn → Gilbert: multiply by 1.2566371. For example, 1 At × 1.2566371 = 1.2566371 Gi.
Ampere-Turns: Current Times Coil Turns
Magnetomotive force is what drives magnetic flux around a magnetic circuit, the same way voltage drives current around an electric circuit. A coil of N turns carrying a current of I amps produces N×I ampere-turns of MMF — double the turns or double the current, and the MMF doubles too. That direct relationship is why engineers designing transformers, motors, solenoids, and electromagnets work backward from a target magnetic field to figure out exactly how many turns of wire, at how many amps, are needed to reach it.
The Gilbert and Rowland's Law
The gilbert is the CGS-electromagnetic (EMU) unit of MMF, defined through Rowland's law — the magnetic circuit's analog of Ohm's law — so that 1 gilbert of MMF driving against 1 unit of magnetic reluctance produces exactly 1 maxwell of magnetic flux. Named after William Gilbert, whose 1600 treatise De Magnete first systematically studied magnetism using scientific experiment, the gilbert equals 10/(4π), or roughly 0.7958, ampere-turns. It still appears in older magnetic-circuit engineering texts and some permanent-magnet industry literature that continues to favor CGS-Gaussian units.
Example
A magnetomotive force of 1 At equals 1.2566371 Gi. For scale, a small relay or sensor coil might need only a few ampere-turns of MMF, a solenoid valve typically needs tens to hundreds of ampere-turns, and a large industrial electromagnet or transformer core can require several kiloampere-turns to reach its rated magnetic field.
Frequently Asked Questions
How many Gilberts are in 1 Ampere Turn?
1 Ampere Turn (At) equals exactly 1.2566371 Gilberts (Gi).
What's the difference between magnetomotive force and magnetic field strength?
Magnetomotive force (measured in ampere-turns) is the total "driving force" a coil applies around an entire magnetic circuit — it depends on current and number of turns alone. Magnetic field strength (measured in amperes per meter) is that driving force spread over a specific length of the circuit's path, similar to how voltage differs from electric field strength (volts per meter). Divide MMF by the path length and you get field strength.
Why is the gilbert not a round number of ampere-turns?
The gilbert comes from the CGS-Gaussian unit system, which was built around centimeters, grams, and seconds rather than the SI's meters, kilograms, and amperes. Its definition via Rowland's law introduces a factor of 4π somewhere in the unit conversion chain, which is why 1 gilbert works out to 10/(4π) ≈ 0.7958 ampere-turns instead of a clean round number.
How do I calculate the ampere-turns needed for an electromagnet?
Multiply the number of turns of wire in the coil by the current flowing through it in amps. A coil with 500 turns carrying 2 amps produces 1,000 ampere-turns of magnetomotive force. The actual magnetic field strength that produces also depends on the length of the magnetic path the flux travels through, which is where the related magnetic field strength (ampere/meter) unit comes in.
Is the abampere-turn still used today?
Rarely in new work — it's a holdover from the 19th-century CGS-electromagnetic unit system, where the abampere (10 amperes) was the base current unit. You'll mostly encounter it when reading or converting older electrical engineering and physics literature published before the SI ampere became the universal standard.