Fabric weight converter
Read a fabric weight on the scale your supplier or customer uses: 200 gsm is 5.898704936329 oz/yd², with exact ounce, pound, yard and foot definitions across eight units. Handy for tech packs, mill cards and online fabric listings. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Numeric fabric weight
- 200
- Source unit
- gsm
- Target unit
- oz/yd2
- Result
- 5.8987049363
- From label
- grams per square meter
- To label
- ounces per square yard
- Gsm
- 200
A fabric weight converter turns an areal density written in grams per square meter, ounces per square yard, ounces per square foot, or related textile units into any other unit in that set without hunting mill cards or rewriting spreadsheet formulas.
Supported fabric weight units and how the conversion is computed
The converter accepts eight areal-density families under stable canonical codes: gsm for grams per square meter, oz/yd2 for avoirdupois ounces per square yard, oz/ft2 for ounces per square foot, kg/m2 for kilograms per square meter, lb/yd2 and lb/ft2 for pounds per yard or foot, g/cm2 for grams per square centimeter, and mg/m2 for milligrams per square meter.
Mass factors follow the exact avoirdupois ounce of twenty-eight point three four nine five two three one two five grams and the exact pound of four hundred fifty-three point five nine two three seven grams.
Area factors use the international yard of zero point nine one four four meters and foot of zero point three zero four eight meters, so one square yard is exactly zero point eight three six one two seven three six square meters and one square foot is exactly zero point zero nine two nine zero three zero four square meters.
Because the intermediate is always gsm, 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. Linear yarn measures such as denier and tex, bulk density, and paper basis-weight systems outside this set are intentionally out of scope so apparel and technical-fabric users get predictable mass-per-area results under one clear SI convention.
For tech packs, mill cards and shop listings
Use the free in-browser fabric weight converter when you need a quick gsm-to-ounces-per-yard, ounces-per-foot-to-gsm, or kilograms-per-meter check while reading a mill card, tech pack, print-media datasheet, or supplier email. 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 merchandisers and engineers expect on paper.
What you can do with it
Apparel tech packs and mill cards
Convert supplier GSM into ounces per square yard (or the reverse) so US and EU fabric specs share one view without hand-written factors.
E-commerce fabric filters and PLM
Normalize mixed gsm and oz/yd² listings so shoppers and product systems compare weight bands consistently across regions.
FAQ
How do I convert fabric weight from gsm to oz/yd²?
The response includes result in ounces per square yard plus the intermediate gsm field.
Which fabric weight units are supported?
Canonical units are gsm, oz/yd2, oz/ft2, kg/m2, lb/yd2, lb/ft2, g/cm2, and mg/m2.
What happens if I send an unknown unit?
The error message names the bad field and lists supported units; validation failures are not charged.
Is the fabric weight converter free?
The browser tool runs free on your device.
Are the conversion factors exact?
Yes. Factors use the exact avoirdupois ounce and pound with the international yard and foot, routed through g/m², with twelve-decimal rounding for stable goldens.
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/fabric-weight \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"value":200,"from":"gsm","to":"oz/yd2"}'const res = await fetch("https://api.kit.forhosting.com/conv/fabric-weight", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"value": 200,
"from": "gsm",
"to": "oz/yd2"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/fabric-weight",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"value": 200,
"from": "gsm",
"to": "oz/yd2"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/fabric-weight", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"value":200,"from":"gsm","to":"oz/yd2"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"value":200,"from":"gsm","to":"oz/yd2"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/fabric-weight", 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": 200,
"from": "gsm",
"to": "oz/yd2"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.fabric_weight",
"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 fabric weight units and how the conversion is computed
Friendly aliases such as g/m², g/m2, ounces per square yard, osy, oz/sq yd, and pounds per square foot are normalized case-insensitively so forms and APIs can pass either short codes or full names, including Unicode superscripts. Every request multiplies the input value by the exact grams-per-square-meter factor for the source, then divides by the 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 weight deltas in inventory or quality 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, quantity, and weight 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 gsm quantity in grams per square meter, the dimensionless factor from source to target, a short formula line suitable for UI display, the method tag fabric_weight_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. Lightweight chiffon around twenty gsm and heavy industrial cloth above one thousand gsm share the same code path, so extreme magnitude pairs remain well-defined as long as IEEE double precision can represent the intermediate product.
Browser use, API pricing, and textile or apparel workflows
Switch to the prepaid API when a product information system, e-commerce fabric filter, apparel PLM tool, technical-textile estimator, or materials pipeline must convert mixed GSM and imperial fabric weights 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 length or area converters when a cut-and-sew pipeline needs several measure families, or call it alone when search traffic is specifically for fabric weight conversion—gsm, oz per square yard, and oz per square foot—rather than a general unit switchboard.
Integration use cases
Technical textiles and print media
Call a prepaid, deterministic fabric weight API from estimators and QA tools with clear invalid_input on unknown units.