Magnetomotive force converter
Switch magnetomotive force between SI and CGS without redoing the four-pi factor: 1 ampere-turn is 1.256637061436 gilberts. Five units, from milliampere-turns to abampere-turns, for magnetic-circuit problems, winding notes and older textbooks. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Numeric magnetomotive force
- 1
- Source unit
- At
- Target unit
- Gb
- Result
- 1.2566370614
- From label
- ampere-turn
- To label
- gilbert
- Ampere turns
- 1
A magnetomotive force converter turns an MMF quantity written in one unit into another without hunting dusty electromagnetic tables or re-deriving the four-pi gilbert factor by hand.
Supported MMF units and how the conversion is computed
The converter accepts five magnetomotive-force families under stable canonical codes: At for the SI ampere-turn, kAt for the kiloampere-turn, mAt for the milliampere-turn, Gb for the CGS gilbert, and abAt for the abampere-turn (also known historically as the biot-turn in electromagnetic units). Factors follow SI and conventional electromagnetic standards: one kiloampere-turn is exactly one thousand ampere-turns, one milliampere-turn is exactly one thousandth of an ampere-turn, one gilbert is exactly ten divided by four pi ampere-turns, and one abampere-turn is exactly ten ampere-turns because one abampere equals ten amperes.
Because the intermediate is always ampere-turns, converting A to B and B to A is consistent up to the published rounding of twelve decimal places, and there is no pairwise matrix that can drift out of sync. Magnetic field strength H, magnetic flux, reluctance, and inductance are intentionally out of scope so motor designers, transformer students, and lab users get predictable MMF-only results under one clear convention.
Where magnetomotive force conversions help
Use the free in-browser magnetomotive force converter when you need a quick ampere-turns-to-gilberts, gilberts-to-abampere-turns, or kiloampere-turns-to-milliampere-turns check while reading a magnetic-circuit problem, a solenoid datasheet, a transformer winding note, or a CGS-era textbook. Open the page, enter the number and units, and copy the result without installing a spreadsheet, a unit library, or a desktop calculator pack. Source inputs follow the same retention rules as other KIT parse items, and results are safe to cache because the algorithm is fully deterministic.
Authors shipping mobile apps or chatbots can map the result and formula fields directly into cards that show both the number and the conversion path students, engineers, and technicians expect on paper.
What you can do with it
Magnetic circuit and transformer design
Convert ampere-turns and kiloampere-turns to gilberts (and back) so winding tables, CGS textbook examples, and SI design notes share one view without hand-written four-pi factors.
Solenoid and electromagnet sizing
Normalize abampere-turns, ampere-turns, and milliampere-turns when legacy EMU datasheets mix with modern SI coil specifications.
FAQ
What is the exact gilbert factor used?
One gilbert equals exactly 10/(4π) ampere-turns. The converter multiplies and divides by that closed-form factor so results stay consistent with SI–CGS electromagnetic definitions.
Is the magnetomotive force converter free?
The browser tool runs free on your device.
How many abampere-turns equal one ampere-turn?
One abampere-turn equals exactly ten ampere-turns, so one ampere-turn equals 0.1 abampere-turn. Send from "At" and to "abAt" (or the reverse) to get the rounded numeric result.
Does it convert magnetic field strength or reluctance?
No. Field strength, magnetic flux, reluctance and inductance are left out on purpose. The converter handles magnetomotive force only: ampere-turns, kiloampere-turns, milliampere-turns, gilberts and abampere-turns.
Can I enter a negative magnetomotive force?
Yes. Negative values are allowed for signed coil values in design calculations, and they convert like any other number. Zero converts to zero in every unit.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/conv/magnetomotive-force \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"value":1,"from":"At","to":"Gb"}'const res = await fetch("https://api.kit.forhosting.com/conv/magnetomotive-force", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"value": 1,
"from": "At",
"to": "Gb"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/magnetomotive-force",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"value": 1,
"from": "At",
"to": "Gb"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/magnetomotive-force", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"value":1,"from":"At","to":"Gb"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"value":1,"from":"At","to":"Gb"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/magnetomotive-force", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"value": 1,
"from": "At",
"to": "Gb"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.magnetomotive_force",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
The browser tool runs free on your device; the prepaid API charges $0.002 per successful item when pipelines need the same contract from servers and automation.
Supported MMF units and how the conversion is computed
Friendly aliases such as ampere-turn, ampere-turns, kiloampere-turn, milliampere-turn, gilbert, gilberts, abampere-turn, abampere-turns, and biot are normalized case-insensitively so forms and APIs can pass either short codes or full names with spaces, hyphens, or underscores. Every request multiplies the input value by the exact ampere-turns-per-unit factor for the source, then divides by the ampere-turns-per-unit factor for the target.
Request shape, response fields, and unknown-unit errors
The error message names the bad field and lists the supported set so clients can correct forms without guessing. Negative values are allowed when you need signed coil MMF in engineering pipelines; zero converts cleanly to zero in every target unit. Send a JSON body with three required fields: value as a finite number, from as the source unit string, and to as the target unit string. Aliases amount and quantity are accepted for value; unit_from and source for from; unit_to and target for to. On success the response echoes the canonical from and to codes, human-readable from_label and to_label strings, the converted result, the intermediate ampere_turns quantity, the dimensionless factor from source to target, a short formula line suitable for UI display, the method tag mmf_si, and the fixed list of units_supported. Missing value, non-finite numbers such as NaN or Infinity, missing unit fields, and any token that does not map to a supported unit fail with invalid_input and are not charged after the engine rejects the request. Identical inputs always yield identical JSON because the path is pure arithmetic with no randomness, no remote lookup, and no dependence on the wall clock, which makes the endpoint safe to pin in continuous-integration goldens and SDK contract tests. Gilbert-scale results and kiloampere-turn-scale results share the same code path, so extreme magnitude pairs remain well-defined as long as IEEE double precision can represent the intermediate ampere-turn product.
Browser use, API pricing, and everyday electromagnetic workflows
Switch to the prepaid API when a magnetic-design CAD plugin, motor-winding calculator, electromagnet sizing tool, physics homework checker, or lab notebook pipeline must convert MMF at scale under a stable KIT contract at $0.002 per successful item; validation failures that raise invalid_input do not consume balance after rejection. Pair this endpoint with electric-current or inductance converters when a product pipeline needs several electromagnetic measure families, or call it alone when search traffic is specifically for magnetomotive force conversion—ampere-turns, gilberts, abampere-turns, kiloampere-turns, and milliampere-turns—rather than a general unit switchboard.
Integration use cases
Homework and electromagnetic pipelines
Convert gilberts for class problems and lab reports with a prepaid, deterministic API and clear invalid_input on unknown units.
Technical questions
How do I convert ampere-turns to gilberts?
Send JSON with value set to your number, from set to "At" (or "ampere-turns"), and to set to "Gb" (or "gilberts"). The response includes result, ampere_turns intermediate, and a formula line.
What happens if I send an unknown unit?
The request fails with invalid_input. The error message names the field and lists supported units: At, kAt, mAt, Gb, and abAt (with common aliases).