Caster sugar cups to grams converter
One US cup of caster sugar weighs 225 g, and half a cup 112.5 g. Enter whole, half or decimal cups from a sponge or meringue recipe and get the grams for your scale, with a weight meant for superfine sugar only. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Cups
- 1
- Grams
- 225
- G per cup
- 225
- Ingredient
- caster_superfine_sugar
- Ingredient label
- caster (superfine) sugar
This caster sugar cups to grams converter turns a volume of caster (superfine) sugar measured in US cups into a stable gram weight using one documented kitchen density so baking scales and cup recipes stay consistent. Caster sugar crystals are finer than ordinary granulated sugar and pack differently in a measuring cup, so a generic sugar chart or a multi-type table that silently maps caster onto granulated can under- or over-weigh meringues, sponges, and syrups. Enter a non-negative number of US cups — whole cups, halves, thirds, or any finite decimal — and the engine multiplies by two hundred twenty-five grams per cup, the fixed culinary constant this landing uses for caster and superfine sugar, then returns grams, the density factor, a short formula string, and a human-readable message you can paste into a recipe note.
What the converter returns and which caster sugar density it uses
Caster sugar — also called superfine sugar or castor sugar in many English-language recipes — is refined white sugar ground to a crystal size between granulated and powdered. Because the crystals are smaller, a leveled US measuring cup holds a different mass than the same cup filled with coarse granulated sugar, which is why bakers who switch between cup recipes and gram scales need a dedicated factor rather than a one-size-fits-all sugar weight.
This tool uses a single fixed density of two hundred twenty-five grams per US cup for caster and superfine sugar. That constant is a widely published culinary convention for caster sugar; it is intentionally not humidity-adjusted, brand-specific, or packed-versus-spooned. There is no brown-sugar path, no powdered-sugar path, and no reverse grams-to-cups path on this landing: those intents belong on dedicated pages so each search query keeps a clear contract.
Invalid cases include a missing cups field, non-finite numbers such as NaN or Infinity, non-numeric strings, amounts above the published magnitude ceiling, and any negative cups value, because a kitchen sugar quantity cannot be negative. The density choice is documented so two different clients never disagree about how many grams sit in one cup of caster sugar when they share this contract.
Where caster sugar cup conversion fits in cooking and software
Home bakers meet this conversion when a British sponge or meringue recipe lists caster sugar in cups and the only scale in the kitchen shows grams, or when an American cup-based cookie formula must be followed with a European gram scale that has no cup marks. Professional pastry kitchens and bakery production sheets convert between cup marks on a measuring jug and gram targets so meringue, buttercream, and syrup batches stay consistent across staff and shifts.
Teachers and culinary students use a fixed density for worksheet keys without trusting opaque calculator apps that silently round a cup of superfine sugar to two hundred grams one day and two hundred twenty-five the next. Product teams call the same contract from scripts to seed deterministic test vectors for recipe importers, to normalize user-entered caster sugar fields before scaling a batch, or to satisfy programming-challenge statements that demand a documented density rather than a hand-waved cup weight.
Prefer this landing when the search intent is specifically caster or superfine sugar cups to grams; use a multi-type sugar converter when you need granulated, brown, and powdered in one request, and keep dedicated flour or honey tools for those ingredients.
What you can do with it
Scale sponge and meringue recipes
Convert US cups of caster (superfine) sugar in family or bakery recipes to grams using the fixed 225 g per cup density.
Bakery production sheets
Normalize caster sugar lines from cup marks to gram targets so meringue and syrup batches stay consistent across staff.
FAQ
What does the caster sugar cups to grams converter cost?
It is free in your browser on this page.
How many grams is one cup of caster sugar?
Under the fixed density used here, one US cup of caster (superfine) sugar is 225 grams.
What happens if cups is negative?
Kitchen sugar quantities cannot be negative, so the task is not billed.
Does this convert granulated or powdered sugar?
No. This landing is dedicated to caster (superfine) sugar at 225 g per US cup. Use a multi-type sugar converter for granulated, brown, or powdered sugar.
Why does caster sugar need its own cup weight?
Its crystals are finer than granulated sugar, so a leveled cup packs a different mass. A generic sugar chart can under- or over-weigh meringues, sponges and syrups, which is why this page uses a factor for caster sugar alone.
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/cook/caster-sugar-cups-to-grams \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"cups":1}'const res = await fetch("https://api.kit.forhosting.com/cook/caster-sugar-cups-to-grams", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"cups": 1
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/cook/caster-sugar-cups-to-grams",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"cups": 1
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/cook/caster-sugar-cups-to-grams", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"cups":1}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"cups":1}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/cook/caster-sugar-cups-to-grams", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"cups": 1
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "cook.caster_sugar_cups_to_grams",
"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
Use it free in the browser while scaling a Victoria sponge or French macaron batch, or call the API at $0.002 per successful request when your product must convert caster sugar cups to grams without re-implementing the density constant.
What the converter returns and which caster sugar density it uses
You send cups, and the response echoes the normalized cups value, the grams total, the g_per_cup factor of two hundred twenty-five, the ingredient key caster_superfine_sugar with a short ingredient_label, the cup_standard string US cup, a formula field restating grams equals cups times two hundred twenty-five, a method tag fixed_density, and a message that restates the conversion in plain English. If validation fails you get invalid_input with a clear message and the request is not charged.
How cups are read so results stay reproducible
Optional leading plus signs and scientific notation on numeric strings are accepted when they parse as finite decimals; embedded spaces, currency symbols, hex prefixes, and non-numeric tokens are rejected so a bad cell does not become a silent wrong batch size. Zero cups is valid and returns zero grams. The preferred field is cups for the magnitude in US cups of caster or superfine sugar. Aliases such as amount, value, quantity, n, and qty map to the same field so spreadsheets, query strings, and typed forms can reuse the contract without renaming columns. Pair the free browser run on this page with the priced API when you need the identical mathematical result inside an automated pipeline without re-implementing the caster sugar density factor yourself. Clients that already hold a multi-ingredient recipe model can call this endpoint only for the caster sugar line and leave flour, butter, and liquid sugar conversions to their own landings.
Where caster sugar cup conversion fits in cooking and software
On this page the work runs entirely in your browser; through the API each successful lookup costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split — free interactive exploration and a priced, identical API — matches the rest of the KIT tier-A catalog and lets you move from a kitchen demo to an automated pipeline without changing the mathematical result.
Integration use cases
Deterministic test fixtures
Generate reproducible caster sugar cup→gram equivalents for unit tests, recipe importers, and CI assertions without re-coding density.
Technical questions
Can I send the amount under a field other than cups?
Yes. Aliases amount, value, quantity, n, and qty are accepted and mapped to the same non-negative US-cups magnitude.