Powdered Sugar: Cups to Grams
A US cup of powdered sugar (also called icing sugar, confectioners sugar) weighs 120 g. Working back the other way, 100 g is about 7/8 cup and 250 g is about 2 1/8 cups. Use the calculator for any amount in between.
💡 Tip: Powdered (icing) sugar clumps, so always sift it before measuring for accurate amounts. It also contains a little cornstarch to prevent caking.
Cups to grams chart for powdered sugar
| Cups | Grams | Ounces |
|---|---|---|
| 1/4 | 30 | 1.06 |
| 1/3 | 40 | 1.41 |
| 1/2 | 60 | 2.12 |
| 2/3 | 80 | 2.82 |
| 3/4 | 90 | 3.17 |
| 1 | 120 | 4.23 |
| 1 1/2 | 180 | 6.35 |
| 2 | 240 | 8.47 |
| 3 | 360 | 12.7 |
Sifted vs unsifted — and a one-minute DIY
Powdered sugar clumps in the bag, so a scooped cup can hold noticeably more than a sifted one. For frostings and glazes where smoothness matters, sift first, then spoon and level — or just weigh out 120g per cup to skip the guesswork.
Run out? Blend 1 cup of granulated sugar with 1 tablespoon of cornstarch until it turns to powder, about a minute in a strong blender. The cornstarch mimics the anti-caking starch in store-bought icing sugar.
Grams to cups chart for powdered sugar
| Grams | Amount | Ounces |
|---|---|---|
| 25 | 1/4 cup | 0.88 |
| 50 | 3/8 cup | 1.76 |
| 75 | 5/8 cup | 2.65 |
| 100 | 7/8 cup | 3.53 |
| 150 | 1 1/4 cups | 5.29 |
| 200 | 1 2/3 cups | 7.05 |
| 225 | 1 7/8 cups | 7.94 |
| 250 | 2 1/8 cups | 8.82 |
| 300 | 2 1/2 cups | 10.6 |
| 400 | 3 1/3 cups | 14.1 |
| 500 | 4 1/8 cups | 17.6 |
Spoon reference: 1 tablespoon ≈ 7.5 g, 1 teaspoon ≈ 2.5 g.
Powdered Sugar against the other sugars & sweeteners
At 120 g per cup, powdered sugar is the lightest of the 10 sugars & sweeteners charted on this site. At the other end of the range, caster sugar weighs 225 g — 88% more for the very same cup.
That gap matters when you substitute by volume: use a cup of allulose where the recipe wanted powdered sugar and you have added about 40 g extra — 33% more than intended. Weighing instead of scooping removes the problem.
Powdered Sugar conversion questions
- How many grams is 1 cup of powdered sugar?
- 1 US cup of powdered sugar weighs about 120 grams, or 4.23 ounces.
- How many grams is 2 cups of powdered sugar?
- 2 cups of powdered sugar is 240g (at 120g per cup), and 3 cups is 360g.
- How many cups is 150g of powdered sugar?
- 150g of powdered sugar is 1¼ cups (150 ÷ 120 = 1.25).
- Is powdered sugar the same as icing sugar or confectioners' sugar?
- Yes — powdered sugar, icing sugar (UK) and confectioners' sugar are three names for the same finely-ground sugar with a little cornstarch added. All weigh about 120g per cup.
- How do I make powdered sugar at home?
- Blend 1 cup of granulated sugar with 1 tablespoon of cornstarch in a high-speed blender for 30–60 seconds until fine and fluffy. Let the dust settle before opening the lid.
- Does sifting change how much powdered sugar weighs?
- Yes. Sifting adds air, so a sifted cup weighs less than a scooped one. That is why recipes specify '1 cup sifted' (sift then measure) versus '1 cup, sifted' (measure then sift) — and why weighing is more reliable.
- How many cups is 100g of powdered sugar?
- About 7/8 cup — that is 100 divided by the 120 g a cup weighs.
- How many cups is 500g of powdered sugar?
- About 4 1/8 cups — that is 500 divided by the 120 g a cup weighs.
- How many grams is ½ cup of powdered sugar?
- Half a US cup of powdered sugar is about 60 grams.