How many grams are in 1 cup of Icing sugar?
One US cup (240 ml) of icing sugar (unsifted) weighs about 120 grams. A US customary cup (236.6 ml) holds about 118 g, a metric cup (250 ml) about 125 g, and an imperial cup (284.1 ml) about 142 g.
Cups of Icing sugar to grams
One US cup (240 ml) of icing sugar (unsifted) weighs about 120 grams (4.2 oz), measured spoon and level.
Icing (powdered/confectioners’) sugar is flour-like: powdery, clumpy and quick to compact. It also loses 10–15 g per cup once sifted, so when you measure relative to sifting changes the number.
Ingredient
120 grams
US cup · icing sugar (unsifted) · spoon and level
More precise value: 120 grams
- Cup standard
- US cup · 240 ml
- Ingredient
- icing sugar (unsifted)
- Method
- spoon and level
- Density
- 0.5 g/ml
- Sources
- USDA FDC · King Arthur
- Reviewed
- 2026-08
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Icing sugar by cup standard
The same volume weighs more in a larger cup. These figures scale the reference weight of 120 g per 240 ml US cup by each cup standard’s exact volume.
| Cups | US cup | US customary cup | Metric cup | Imperial cup |
|---|---|---|---|---|
| ⅛ | 15 g | 15 g | 16 g | 18 g |
| ¼ | 30 g | 30 g | 31 g | 36 g |
| ⅓ | 40 g | 39 g | 42 g | 47 g |
| ½ | 60 g | 59 g | 63 g | 71 g |
| ⅔ | 80 g | 79 g | 83 g | 95 g |
| ¾ | 90 g | 89 g | 94 g | 107 g |
| 1 | 120 g | 118 g | 125 g | 142 g |
| 1½ | 180 g | 177 g | 188 g | 213 g |
| 2 | 240 g | 237 g | 250 g | 284 g |
icing sugar (unsifted), spoon and level. Reviewed 2026-08.
Tablespoons and teaspoons
Spoon measures use the US definitions: 1 tablespoon = 14.79 ml (16 per cup) and 1 teaspoon = 4.93 ml (3 per tablespoon).
| Measure | Grams (g) | Ounces (oz) |
|---|---|---|
| 1 tsp | 2.5 | 0.09 |
| 1 tbsp | 7.4 | 0.26 |
| 2 tbsp | 14.8 | 0.52 |
| 4 tbsp (¼ cup) | 29.6 | 1.04 |
| 8 tbsp (½ cup) | 59.1 | 2.09 |
| 16 tbsp (1 cup) | 118.3 | 4.17 |
How to measure Icing sugar by volume
- Spoon unsifted icing sugar into the cup and level it — that matches our 120 g figure.
- If your recipe says “1 cup sifted icing sugar”, sift first, then measure (about 100 g).
- If it says “1 cup icing sugar, sifted”, measure first, then sift.
Why the weight varies
Icing (powdered) sugar compacts easily; sifting can reduce a cup by 10–15 g.
Frostings and glazes are mostly sugar, so a 20 g swing per cup visibly changes thickness. Word order in the recipe — “sifted sugar” versus “sugar, sifted” — is the detail that decides which weight applies.
Which value we publish, and why
We publish 120 g per US cup unsifted (USDA FoodData Central; 100 g sifted); King Arthur lists 113 g.
Values you may see elsewhere
Sources: USDA FDC · King Arthur . Reference weight verified against USDA FDC, King Arthur. Reviewed 2026-08. Conversions are estimates — ingredient weight varies with packing and brand.
Frequently asked questions
How many grams is 1 tablespoon of Icing sugar?
One US tablespoon (14.79 ml) of icing sugar (unsifted) weighs about 7.4 g, and one teaspoon (4.93 ml) about 2.5 g.
How many ounces is 1 cup of Icing sugar?
One US cup of icing sugar (unsifted) weighs about 4.2 oz (120 g). Note these are weight ounces — for liquids, don’t confuse them with fluid ounces, which measure volume.