Magnetic reluctance converter
Convert magnetic reluctance across nine units, from inverse henries and ampere-turns per weber to the CGS gilbert per maxwell: 1 H⁻¹ is exactly 1 At/Wb, so core notes, design guides and older textbooks agree. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Value
- 1
- From
- H^-1
- To
- At/Wb
- Result
- 1
- From label
- inverse henry
- To label
- ampere-turn per weber
- Inv h
- 1
A magnetic reluctance converter turns a quantity written in one reluctance unit into another without hunting conversion tables, CGS footnotes, or spreadsheet macros.
Supported units and how the conversion is computed
The converter accepts nine magnetic reluctance families under stable canonical codes: H^-1 for the SI inverse henry (reciprocal henry), At/Wb for ampere-turns per weber, A/Wb for amperes per weber, rel for the practical magnetic-reluctance unit equal to one ampere-turn per weber, mH^-1 for inverse millihenry, uH^-1 for inverse microhenry (ASCII form; Greek mu micro symbols are also accepted), nH^-1 for inverse nanohenry, kH^-1 for inverse kilohenry, and Gb/Mx for gilbert per maxwell in the CGS electromagnetic system.
SI identities are exact by definition: one inverse henry equals one ampere-turn per weber equals one ampere per weber equals one rel. Inverse-henry multiples follow SI engineering standards: one inverse millihenry is exactly one thousand inverse henries, one inverse microhenry is one million, one inverse nanohenry is one billion, and one inverse kilohenry is one thousandth of an inverse henry.
The CGS link uses the exact factors one ampere-turn equals four pi over ten gilbert and one weber equals one hundred million maxwell, so one gilbert per maxwell equals ten to the nine over four pi inverse henries. Because the intermediate is always inverse henries, 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.
Inductance, permeance, magnetic flux density, and magnetomotive force alone are intentionally out of scope so magnetic-circuit users get predictable reluctance-only results under one clear convention.
Where reluctance conversions come in handy
Use the free in-browser magnetic reluctance converter when you need a quick inverse-henry to ampere-turn-per-weber, rel to gilbert-per-maxwell, or millihenry-inverse to nanohenry-inverse check while reading a magnetic circuit datasheet, transformer core note, electromagnet design guide, SPEA or IEC homework problem, or older CGS textbook table. 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, technicians, and engineers expect on paper.
What you can do with it
Magnetic circuits and transformer cores
Convert At/Wb and H^-1 reluctance values from core geometry notes so FEA tools, SPEA worksheets, and magnetics databases share one SI view without hand-written 4π CGS factors.
Legacy CGS textbooks and lab notes
Normalize gilbert per maxwell figures from older electromagnetics texts into inverse henries or ampere-turns per weber when modern homework and simulation expect SI.
FAQ
Which magnetic reluctance units does this converter support?
Inverse henry (H^-1), ampere-turn per weber (At/Wb), ampere per weber (A/Wb), rel, inverse millihenry (mH^-1), inverse microhenry (uH^-1 or µH^-1), inverse nanohenry (nH^-1), inverse kilohenry (kH^-1), and gilbert per maxwell (Gb/Mx).
Are inverse henry, At/Wb, A/Wb and rel the same?
Yes in SI dimension: one inverse henry equals one ampere-turn per weber equals one ampere per weber equals one rel. The converter returns the canonical target code while the numeric result is one-to-one among these four labels.
What happens if I send an unknown unit?
The message names the field and lists supported units. Validation failures are not charged.
Is the magnetic reluctance converter free?
The browser tool runs free on your device.
Why is an inverse millihenry larger than an inverse henry?
Because the prefix sits under the fraction. One per millihenry is 1000 inverse henries, one per microhenry is a million, and one per kilohenry is only a thousandth of an inverse henry.
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/reluctance \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"value":1,"from":"H^-1","to":"At/Wb"}'const res = await fetch("https://api.kit.forhosting.com/conv/reluctance", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"value": 1,
"from": "H^-1",
"to": "At/Wb"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/reluctance",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"value": 1,
"from": "H^-1",
"to": "At/Wb"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/reluctance", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"value":1,"from":"H^-1","to":"At/Wb"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"value":1,"from":"H^-1","to":"At/Wb"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/reluctance", 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": "H^-1",
"to": "At/Wb"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.reluctance",
"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 units and how the conversion is computed
Friendly aliases such as 1/H, inverse henry, ampere turns per weber, gilberts per maxwell, per millihenry, and magnetic ohm are normalized case-insensitively so forms and APIs can pass either short codes or full names. Every request multiplies the input value by the exact inverse-henry factor for the source, then divides by the inverse-henry 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 reluctance in modeling 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 inv_h quantity in inverse henries, the dimensionless factor from source to target, a short formula line suitable for UI display, the method tag reluctance_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-per-maxwell scale results and nanohenry-inverse scale results share the same code path, so extreme magnitude pairs remain well-defined as long as IEEE double precision can represent the intermediate inverse-henry product.
Browser use, API pricing, and everyday workflows
Switch to the prepaid API when an electromagnetics CAD plugin, magnetic materials database, motor design tool, sensor calibration pipeline, physics homework checker, or instrumentation service must convert reluctance 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 inductance or magnetic-flux converters when a product pipeline needs both reluctance and L or Φ, or call it alone when search traffic is specifically for magnetic reluctance conversion—inverse henry, ampere-turn per weber, rel, gilbert per maxwell—rather than a general unit switchboard.
Integration use cases
Motor, sensor, and homework pipelines
Convert mH^-1 through rel and H^-1 for design automation and class problems with a prepaid, deterministic API and clear invalid_input on unknown units.
Technical questions
How do I convert 1 inverse henry to gilberts per maxwell?
Send JSON with value: 1, from: "H^-1", to: "Gb/Mx". The result is 4π×10⁻⁹ (about 1.25663706144e-8) Gb/Mx, plus an inv_h intermediate and a readable formula.