Walk into any kitchen and you will find at least three different bags that all call themselves "sugar": fine white granules, moist brown crystals, and a powder fine enough to float. Each has a different weight per cup, a different measuring rule, and a different job in baking. Getting them confused — or measuring them all the same way — quietly sabotages more desserts than almost any other ingredient mix-up.
The weights that matter
| Type | Grams per cup | How to measure |
|---|---|---|
| Granulated (white) | 200 | spoon & level |
| Brown sugar | 220 | packed firmly |
| Powdered (confectioners') | 120 | spoon & level, then sift |
| Caster (superfine) | 190 | spoon & level |
| Demerara / turbinado | 200 | spoon & level |
| Muscovado | 230 | packed firmly |
Granulated sugar is one of the few ingredients where volume measurement is genuinely reliable: the crystals are uniform, so a spooned-and-levelled cup is almost always close to 200 g. That is why sugar recipes convert so cleanly — 1 cup = 200 g is a rule you can trust, unlike flour.
Brown sugar: packed or loose?
Brown sugar is granulated sugar coated in molasses, which makes the crystals stick together. A loosely scooped cup of brown sugar weighs barely 180 g because of the air trapped between clumps; a firmly packed cup holds about 220 g. Recipes that say "1 cup brown sugar, packed" expect the 220 g number — and they say "packed" for a reason.
To pack properly: press the sugar into the cup with the back of a spoon, add more, press again, and continue until it holds the cup's shape when you turn it out. If your brown sugar has hardened into a brick, soften it with a slice of bread in an airtight container overnight, or heat it gently in the microwave with a damp paper towel for 20-second bursts.
Our grams to cups converter assumes packed brown sugar (220 g/cup) and says so on the ingredient row — because the difference between 180 and 220 g per cup changes cookies from crisp to cakey.
Powdered sugar and the lump problem
Powdered (confectioners') sugar is granulated sugar ground with a little cornstarch to stop caking. It is light and fluffy, so a spooned cup weighs only about 120 g. It also clumps as it sits, which means the same cup can drift between 110 and 130 g depending on how much you stir it.
The rule for glaze: sift it first, then measure. If a recipe calls for "1 cup powdered sugar, sifted", the author wants you to sift before measuring — the reverse order ("sifted, then measured") gives a lighter cup. For a stable glaze, most bakers weigh instead: 240 g powdered sugar plus 2–3 tablespoons of milk makes a classic drizzle.
Caster sugar: the baker's default in many countries
In the UK, Australia and New Zealand, caster (superfine) sugar is the standard baking sugar because it dissolves faster into meringues, sponges and custards. It is slightly finer than US granulated, so a cup weighs a touch less: about 190 g vs 200 g. US granulated sugar can substitute for caster sugar in almost any recipe — pulse it in a food processor for 30 seconds if you want the finer texture for meringues.
Liquid sugars: a different family
Honey, maple syrup, molasses and golden syrup are "sugars" in the culinary sense, but they are liquids, and their weights are completely different — one cup of honey weighs about 340 g, nearly double a cup of granulated sugar. Swapping granulated for liquid sugar also requires reducing the recipe's liquid. We cover this in depth in our liquid sweeteners guide.
Why sugar type changes your bake
Beyond weight, sugar type controls texture through water: brown sugar's molasses is hygroscopic, meaning it attracts and holds moisture. Cookies made with all brown sugar stay chewy for days; cookies made with all granulated sugar turn crisp and spread more. Powdered sugar contains cornstarch, which thickens and stabilises — useful in frosting, but wrong for creaming. When a recipe specifies a type, that is not fussiness; it is the recipe telling you which physical properties it depends on.
Substituting one sugar for another
- Granulated → caster: 1:1 by weight, nearly always fine.
- Granulated → brown: replace by weight, and expect more moisture, deeper flavour and darker colour. Reduce liquid slightly for very wet recipes.
- Brown → granulated: add molasses (1 tbsp per 220 g cup) if you want the moisture back.
- Granulated → powdered: avoid for creamed batters; use only in recipes designed for it.
The converter and reverse converter handle every sugar type above, with the correct measuring method built into each density. Measure sugar by weight once, and the bag-to-bag variation that makes volume sugar unpredictable disappears entirely.