Quick answer: One US cup of granulated sugar weighs about 198 g, which most recipes round to 200 g. Caster sugar is about 190 g per cup, packed soft brown sugar about 213 g, and icing sugar only about 113 g. So half a cup of granulated sugar is roughly 100 g, a very handy figure to remember.
Sugar is far easier to convert than flour because it pours and packs consistently, but the type of sugar makes a big difference. A cup of icing sugar weighs little more than half a cup of granulated. This chart covers the sugars sold in British shops and sits within the wider UK cooking measurements guide.
How many grams of sugar are in a cup?
A US cup of granulated sugar is 198 g, or about 7 oz. The figure comes from the King Arthur Baking ingredient weight chart. Many other American sources use a round 200 g, and the 1% difference will not affect any home bake.
Crystal size explains most of the spread. Granulated and caster sugar settle into a dense layer with little air between the grains. Brown sugar is pressed into the cup, which squeezes out air and pushes its weight higher still. Icing sugar is a fine powder that traps a lot of air, so a cupful weighs much less.
Cups to grams sugar chart
Find the cup measure, then read across to your sugar. All figures are for US cups and are rounded to the nearest gram.
| US cups | Granulated | Caster | Soft brown (packed) | Icing sugar |
|---|---|---|---|---|
| ⅛ cup | 25 g | 24 g | 27 g | 14 g |
| ¼ cup | 50 g | 48 g | 53 g | 28 g |
| ⅓ cup | 66 g | 63 g | 71 g | 38 g |
| ½ cup | 99 g | 95 g | 107 g | 57 g |
| ⅔ cup | 132 g | 127 g | 142 g | 75 g |
| ¾ cup | 149 g | 143 g | 160 g | 85 g |
| 1 cup | 198 g | 190 g | 213 g | 113 g |
| 1½ cups | 297 g | 285 g | 320 g | 170 g |
| 2 cups | 396 g | 380 g | 426 g | 226 g |
| 3 cups | 594 g | 570 g | 639 g | 339 g |
Three-quarters of a cup of granulated sugar is 149 grams, and two cups come to 396 grams, so a 1 kg bag holds just over five cups.
What are American sugars called in the UK?
Most American sugars have a direct British equivalent under a different name. Use this table to pick the right bag before you weigh it.
| US recipe says | Buy in the UK | Grams per US cup |
|---|---|---|
| Sugar, white sugar, granulated sugar | Granulated sugar | 198 g |
| Superfine sugar, baker’s sugar | Caster sugar | 190 g |
| Light or dark brown sugar, packed | Light or dark soft brown sugar | 213 g |
| Powdered or confectioners’ sugar | Icing sugar | 113 g (unsifted) |
| Demerara sugar | Demerara sugar | 220 g |
| Turbinado or raw sugar | Demerara is the closest match | 180 g (turbinado) |
Caster sugar is often the better choice for American cake recipes even when they say “sugar”, because its finer crystals dissolve more readily when creamed with butter. Swap it in at the same weight, not the same cup measure.
What does “packed” brown sugar mean?
Packed means pressed firmly into the cup until it holds its shape when turned out. American recipes almost always measure brown sugar this way, and the 213 g figure assumes it. Spooned loosely, the same cup would weigh noticeably less. If a recipe says “lightly packed”, aim for a little under 213 g; if it gives no instruction, assume packed.
How many cups is 100 g of sugar?
100 g of granulated sugar is just over half a US cup. Because a cup is so close to 200 g, the conversion is unusually easy to do in your head: halve the grams to get hundredths of a cup.
| Granulated sugar | US cups | Practical measure |
|---|---|---|
| 50 g | 0.25 | ¼ cup |
| 100 g | 0.51 | ½ cup |
| 150 g | 0.76 | ¾ cup |
| 200 g | 1.01 | 1 cup |
| 250 g | 1.26 | 1¼ cups |
| 300 g | 1.52 | 1½ cups |
| 400 g | 2.02 | 2 cups |
How much does a cup of honey or syrup weigh?
Liquid sugars are much denser than granulated sugar: a cup of honey weighs about 336 g. That figure is sixteen US tablespoons at 21 g each. King Arthur gives maple syrup and corn syrup at about 312 g per cup and molasses, the nearest US product to black treacle, at about 340 g. For sticky syrups, weighing straight into the bowl on zeroed scales avoids scraping out a cup.
Flour behaves very differently from sugar in a cup; the cups to grams flour chart explains why, and the guide to converting American recipes covers butter, liquids and oven temperatures in one place.
Frequently asked questions
How many grams is 1 cup of sugar?
One US cup of granulated sugar is about 198 g, usually rounded to 200 g. Caster sugar is about 190 g per cup.
How many grams is half a cup of sugar?
Half a US cup of granulated sugar is about 99 g, so 100 g is a good working figure. Half a cup of packed brown sugar is about 107 g.
How many grams is 1 cup of icing sugar?
One US cup of unsifted icing sugar is about 113 g. Sifted icing sugar holds more air, so a cup weighs less.
Can I use caster sugar instead of granulated in American recipes?
Yes. Use the same weight rather than the same cup measure. A cup of granulated sugar is 198 g, so weigh out 198 g of caster sugar.
Is a cup of brown sugar heavier than white sugar?
Yes, when packed. A packed US cup of soft brown sugar is about 213 g, compared with 198 g for granulated white sugar.
Sources
- King Arthur Baking: ingredient weight chart (sugar, honey and syrup weights)
- NIST: US customary to metric conversions (cup and tablespoon volumes)