Sugars & Syrups
Convert cups of caster sugar to grams
One cup of caster sugar weighs about 225 g, and half a cup comes to roughly 113 g. Enter any amount below to convert it, or use the chart further down as a quick reference while you cook.
1 cup of caster sugar =
225 g
- oz
- 7.94
- kg
- 0.225
- lb
- 0.496
Caster Sugar: 225 g per US cup · FAO / INFOODS density database. Caster (superfine) sugar has smaller crystals that pack tighter than granulated sugar, so a cup weighs more.
Full caster sugar chart →Caster Sugar at a glance
Every number on this page comes from a single figure: 225 grams per US cup (FAO / INFOODS density database).
- 1 cup
- 225 g
- 1 tablespoon
- 14.1 g
- 1 teaspoon
- 4.69 g
- 1 cup in ounces
- 7.94 oz
- 100 g in cups
- 0.444 cups
- Density
- 0.95 g/ml
cups to grams chart for caster sugar
Print it, screenshot it, or bookmark this page — these are the amounts recipes ask for most often.
| Cups (US) | Grams | Ounces (weight) | Pounds |
|---|---|---|---|
| 1/8 cup | 28.1 g | 0.992 oz | 0.062 lb |
| 1/4 cup | 56.3 g | 1.98 oz | 0.124 lb |
| 1/3 cup | 75 g | 2.65 oz | 0.165 lb |
| 1/2 cup | 113 g | 3.97 oz | 0.248 lb |
| 2/3 cup | 150 g | 5.29 oz | 0.331 lb |
| 3/4 cup | 169 g | 5.95 oz | 0.372 lb |
| 1 cup | 225 g | 7.94 oz | 0.496 lb |
| 1 1/2 cup | 338 g | 11.9 oz | 0.744 lb |
| 2 cup | 450 g | 15.9 oz | 0.992 lb |
| 3 cup | 675 g | 23.8 oz | 1.49 lb |
| 4 cup | 900 g | 31.7 oz | 1.98 lb |
How this conversion is calculated
Volume-to-weight conversions are only as good as the density behind them. We treat caster sugar as 225 g per US customary cup, which works out to 0.951 g/ml. From there:
- Your cups figure is converted into millilitres or grams using standard unit sizes (cup = 237 ml).
- The density above bridges volume and weight in whichever direction you need.
- The result is rounded the way a cook would round it — to the nearest gram, or to a usable fraction such as 1/2 cups.
Measuring caster sugar accurately
Caster (superfine) sugar has smaller crystals that pack tighter than granulated sugar, so a cup weighs more.
If a recipe matters to you — bread, macarons, anything with a tight hydration or ratio — weigh it. A £10 digital scale removes the single largest source of variation in home baking, and it is faster than washing three measuring cups.
When cups are fine
- Liquids measured in a proper jug, where volume is the honest unit anyway.
- Forgiving savoury cooking: soups, stews, stir-fries, marinades.
- Small amounts of leaveners and spices, as long as you use level spoons.
Frequently asked questions
How many grams are in 1 cup of caster sugar?
1 cup of caster sugar is 225 g. This is based on a density of 225 g per US cup.
How many grams are in 2 cups of caster sugar?
2 cups of caster sugar is 450 g, and 113 g for half a cup.
How much is 100 g of caster sugar in cups?
100 g of caster sugar is about 1/2 cups. Weight is always the more reliable measurement, so use a scale when the recipe gives grams.
Why do other sites give a different number for caster sugar?
Caster (superfine) sugar has smaller crystals that pack tighter than granulated sugar, so a cup weighs more.
Do UK and Australian cups give the same result?
No. A US customary cup is 236.6 ml, a metric cup used in Australia and New Zealand is 250 ml, and an old UK imperial cup is 284 ml. Our default is the US cup, but you can pick metric cups in the converter.