Magnetic susceptibility converter
Move a susceptibility value between SI and CGS without four-pi tables: 1 in SI volume units is 0.079577471546 in CGS volume units. Volume, mass and molar forms are covered, and density or molar mass is asked only when a step needs it. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Value
- 1
- Source unit
- si_vol
- Target unit
- cgs_vol
- Result
- 0.0795774715
- From label
- SI volume magnetic susceptibility (dimensionless)
- To label
- CGS volume magnetic susceptibility (emu)
- From family
- volume
A magnetic susceptibility converter turns a χ value written in one electromagnetic convention into another without re-deriving four-pi tables or hunting textbook appendices for mass and molar factors. Identical inputs always produce identical outputs with no network calls, no model sampling, and no clock dependence.
Supported units and the exact SI/CGS conversion factors
Within a family the engine multiplies by an exact fixed factor: SI volume equals four pi times CGS volume; SI mass equals four pi times ten to the minus three times CGS mass; SI molar equals four pi times ten to the minus six times CGS molar. Crossing from volume to mass or molar (or the reverse) requires a positive density in kilograms per cubic metre because mass susceptibility is volume susceptibility divided by density in the matching system.
Crossing into or out of molar units also requires a positive molar mass in grams per mole so the mass-to-molar step is well defined. Magnetic permeability, magnetic moment alone, and magnetomotive force are intentionally out of scope so materials scientists, solid-state students, and lab users get predictable χ-only results under one clear convention.
Where susceptibility conversions help in materials work
Use the free in-browser magnetic susceptibility converter when you need a quick SI-to-CGS volume χ check, a mass susceptibility unit swap between cubic metres per kilogram and cubic centimetres per gram, or a molar conversion while reading a solid-state problem, a SQUID magnetometry note, a materials datasheet, or a CGS-era textbook. Open the page, enter the number and units, supply density and molar mass only when the families require them, 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, formula, and factors fields directly into cards that show both the number and the four-pi conversion path students, engineers, and technicians expect on paper.
What you can do with it
SQUID and VSM lab data
Convert SI volume χ from instrument software into CGS volume or mass susceptibility for papers and legacy analysis scripts that still expect emu-based tables.
Materials databases and datasheets
Normalize mass susceptibility between m³/kg and cm³/g (emu/g) when merging vendor CGS values with SI catalogue rows, using density when volume χ is also present.
FAQ
What is the factor between SI and CGS mass susceptibility?
SI mass susceptibility (m³/kg) equals 4π × 10⁻³ times CGS mass susceptibility (cm³/g or emu/g). Same-family mass conversions do not require density.
When do I need density and molar mass?
Density in kg/m³ is required when converting between volume and mass or molar families. Molar mass in g/mol is required when a conversion involves molar units across families. Same-family SI↔CGS pairs only need value, from, and to.
Is the magnetic susceptibility converter free?
The browser tool runs free on your device.
Why does SI volume susceptibility differ from CGS by four pi?
The two conventions differ by an exact factor of four pi for volume susceptibility. So 1 SI volume unit becomes 0.079577471546 CGS units, and going the other way multiplies by four pi.
Can magnetic susceptibility be negative?
Yes. Diamagnetic materials have negative susceptibility, so negative values are accepted and converted like any other. 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/magnetic-susceptibility \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"value":1,"from":"si_vol","to":"cgs_vol"}'const res = await fetch("https://api.kit.forhosting.com/conv/magnetic-susceptibility", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"value": 1,
"from": "si_vol",
"to": "cgs_vol"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/magnetic-susceptibility",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"value": 1,
"from": "si_vol",
"to": "cgs_vol"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/magnetic-susceptibility", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"value":1,"from":"si_vol","to":"cgs_vol"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"value":1,"from":"si_vol","to":"cgs_vol"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/magnetic-susceptibility", 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": "si_vol",
"to": "cgs_vol"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.magnetic_susceptibility",
"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 the exact SI/CGS conversion factors
The converter accepts six magnetic-susceptibility families under stable canonical codes: si_vol for dimensionless SI volume susceptibility χ_v, cgs_vol for CGS volume susceptibility (often written in emu), si_mass for SI mass susceptibility in cubic metres per kilogram, cgs_mass for CGS mass susceptibility in cubic centimetres per gram or emu per gram, si_molar for SI molar susceptibility in cubic metres per mole, and cgs_molar for CGS molar susceptibility in cubic centimetres per mole. Friendly aliases such as si, cgs, m3/kg, cm3/g, emu/g, m3/mol, cm3/mol, and phrases like SI volume or CGS mass are normalized case-insensitively so forms and APIs can pass either short codes or full names with spaces, hyphens, or underscores.
Request shape, response fields, density, 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 because diamagnetic materials carry negative χ; 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. Optional density (aliases density_kg_m3 and rho) supplies mass density in kilograms per cubic metre when volume and mass or molar families mix. Optional molar_mass (aliases molar_mass_g_mol and M) supplies molar mass in grams per mole when a molar unit is involved across families. Aliases amount, quantity, and chi 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, from_family and to_family tags, the converted result, the dimensionless factor from source to target when defined, the intermediate chi_si_vol when the path exposes SI volume susceptibility, a short formula line suitable for UI display, the method tag magnetic_susceptibility_si_cgs, the fixed list of units_supported, and a factors object documenting the three SI-per-CGS constants. Missing value, non-finite numbers such as NaN or Infinity, missing unit fields, unknown unit tokens, missing density when required, missing molar mass when required, and non-positive density or molar mass all 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.
Browser use, API pricing, and everyday materials-science workflows
Switch to the prepaid API when a materials database, magnetometry pipeline, homework checker, or lab notebook must convert susceptibility 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 magnetomotive-force or electric-current converters when a product pipeline needs several electromagnetic measure families, or call it alone when search traffic is specifically for magnetic susceptibility conversion—SI volume, CGS volume, mass, and molar χ—rather than a general unit switchboard.
Integration use cases
Homework and solid-state pipelines
Convert molar and volume susceptibility for class problems with exact 4π factors, prepaid deterministic API calls, and clear invalid_input on unknown units.
Technical questions
How do I convert SI volume magnetic susceptibility to CGS?
Send JSON with value, from set to si_vol (or si), and to set to cgs_vol (or cgs). The result uses χ_SI = 4π χ_CGS, so χ_CGS = χ_SI / (4π).
What happens if I send an unknown unit?
The request fails with invalid_input. The error message names the field and lists supported units: si_vol, cgs_vol, si_mass, cgs_mass, si_molar, and cgs_molar.