Cups of Powdered Sugar to Grams
Convert cups of unsifted powdered sugar to grams — sifting drops the weight about 20%.
Updated
grams of powdered sugar (unsifted)
113g
1.00 cups of powdered sugar (unsifted) = 113 g
Values use the 240 ml US cup, spoon-and-level — your bag’s label may differ slightly.
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In short
How many grams is 1 cup of powdered sugar?
One cup of unsifted powdered sugar is 113 grams, matching King Arthur Baking, which lists 2 cups at 227 g. Half a cup is about 57 g and two cups are 226 g. A standard 1 pound box therefore holds roughly 4 cups unsifted, which is the conversion most frosting recipes quietly assume.
Sifting adds air, so a cup measured after sifting weighs less — read whether the recipe says sifted before or after the word sugar.
Cups to grams — quick reference
| Cups | Powdered sugar (unsifted) (g) |
|---|---|
| ¼ | 28 g |
| ⅓ | 38 g |
| ½ | 57 g |
| ⅔ | 75 g |
| ¾ | 85 g |
| 1 | 113 g |
| 1½ | 170 g |
| 2 | 226 g |
The formula, worked line by line
Cups of unsifted powdered sugar to grams is one multiplication by 113, the weight of a 240 ml cup spooned in and levelled without sifting. Fractions scale linearly, so a quarter cup is a quarter of the grams and there is nothing else to adjust.
The density carries a state, not a tolerance. It describes the sugar as it comes out of the box. Sift before measuring and the same cup holds a lighter, airier fill, which is why the sequence a recipe specifies changes the answer even though the formula does not.
grams = cups × 113
cups = grams ÷ 113
grams per tablespoon = 113 ÷ 16 ≈ 7.1
1 lb box ÷ 113 ≈ 4 cups unsifted- Recipe calls for
- 4 cups of powdered sugar
- At the engine density
- 4 × 113 = 452 g
- A standard 1 lb box
- 454 g
- Sugar to weigh
- 452 g, in effect the whole box
Weighing confirms that in a second rather than after four passes with a measuring cup. Half the batch is 2 × 113 = 226 grams.
Run the other way, a European recipe asking for 250 grams of icing sugar is 250 ÷ 113 = 2.2 cups, or two cups plus a little over three tablespoons. Awkward in cups, trivial on a scale, and a good illustration of why bakers who make icing regularly stop reaching for the measuring cup at all.
A note on where this sits against the other sugars, cup for cup at the same 240 ml measure, with unsifted powdered sugar the odd one out on the shelf.
- Powdered sugar, unsifted
- 113 g
- Granulated sugar
- 200 g
- Brown sugar, packed
- 213 g
Barely half the weight of the sugars beside it on the shelf.
That is a milling difference rather than a chemical one — it is the same sucrose, ground finer and holding far more air — but it means a cup-for-cup substitution between sugars misses badly, and the mistake is easy to make because all three look like sugar in a cup.
How to use the cups of powdered sugar to grams
Type the cups and read the grams, or tap Swap to convert a gram figure back into cups. The density on this page is 113 grams for an unsifted 240 ml cup, which lines up with King Arthur Baking, whose chart gives two cups of confectioners’ sugar as 227 grams.
Powdered sugar, confectioners’ sugar and icing sugar are three names for the same product: ordinary granulated sugar milled to a fine powder with a small amount of anti-caking starch, usually cornstarch, blended in to keep it flowing. The American packaging often carries a 10X designation, which refers to how fine the mill is rather than to any difference in composition, so any of these will behave the same way in a buttercream.
What does vary a little between brands is the proportion of starch and how finely the sugar has been milled, neither of which the box tells you in any useful form.
113 g
Unsifted cup
spooned in and levelled
7 g
Per level tablespoon
4 cups
In a 1 lb box
454 ÷ 113
The complication with this sugar is air. The particles are fine enough to behave almost like a fluid, they cling to each other and to the sides of the container, and they trap pockets that a heavier crystal would crush.
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That makes the fill method matter more than it does for granulated sugar, and it makes sifting a genuine variable rather than a cosmetic step. Sifting pushes the sugar through a mesh and aerates it on the way, so the same cup afterwards contains fewer grams of sugar and more air. This page publishes the unsifted figure, which is what King Arthur lists.
The sugar it started out as
Powdered sugar is granulated sugar milled fine, and the unmilled version weighs 200 grams a cup against 113 here, so the two are not interchangeable by volume.
Open cups of granulated sugar →Weighing removes the ambiguity in one move: the grams are the grams whether the sugar has been through a sieve or not, so you weigh first and then sift purely for texture.
Sift you should, though, for anything whisked smooth — royal icing, buttercream, glazes and fillings all turn gritty if lumps survive into the mixing bowl, and powdered sugar clumps readily because the fine particles and the cornstarch pull moisture out of the air. For dusting a cake or a tray of doughnuts no measurement is required at all; just push a little through a fine sieve as you go. The values here use a 240 ml cup.
Unsifted powdered sugar from a single tablespoon to a two-pound bag, in grams, weight ounces and level tablespoons, so a frosting recipe written in boxes, cups or spoons converts in one place.
| Amount | Grams (unsifted) | Ounces (weight) | Level tablespoons |
|---|---|---|---|
| 1 tablespoon | 7 g | 0.25 oz | 1 Tbsp |
| 2 tablespoons | 14 g | 0.50 oz | 2 Tbsp |
| ¼ cup | 28 g | 1.00 oz | 4 Tbsp |
| ⅓ cup | 38 g | 1.34 oz | 5⅓ Tbsp |
| ½ cup | 57 g | 2.01 oz | 8 Tbsp |
| ⅔ cup | 75 g | 2.65 oz | 10⅔ Tbsp |
| ¾ cup | 85 g | 3.00 oz | 12 Tbsp |
| 1 cup | 113 g | 3.99 oz | 16 Tbsp |
| 1½ cups | 170 g | 6.00 oz | 24 Tbsp |
| 2 cups | 226 g | 7.97 oz | 32 Tbsp |
| 3 cups | 339 g | 11.96 oz | 48 Tbsp |
| 4 cups (about a 1 lb box) | 452 g | 15.94 oz | 64 Tbsp |
| 8 cups (about a 2 lb bag) | 904 g | 31.89 oz | 128 Tbsp |
| 1 kg bag | 1,000 g | 35.27 oz | 142 Tbsp |
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Why the word order in the recipe changes the amount
The word order in a recipe is not a stylistic detail, it is an instruction about sequence. “1 cup sifted powdered sugar” means sift the sugar first and then measure a cup of the sifted result. “1 cup powdered sugar, sifted” means measure a cup of sugar as it comes and sift it afterwards, using the sieve only to break up lumps.
The two readings give you different amounts of sugar. The same ambiguity turns up in flour recipes for exactly the same reason, but powdered sugar is where it does the most visible damage, because an icing has almost nothing else in it to hide behind.
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Questions people ask
How many grams is 1 cup of powdered sugar?
113 grams unsifted, spooned into the cup and levelled. King Arthur Baking gives two cups of confectioners’ sugar as 227 grams, which is the same density. Half a cup is about 57 grams, three-quarters is 85 grams and two cups are 226 grams. If a recipe hands you sifted sugar to measure, a cup of it will weigh less than 113 grams, because sifting works air into the powder — which is why weighing is the shortcut past the whole question.
Does sifting change how much sugar I get?
Yes, when you sift before measuring. Sifting pushes the sugar through a fine mesh and aerates it, so the same cup afterwards holds more air and fewer grams of actual sugar. That matters most in icings and glazes, where the sugar-to-liquid ratio is what decides whether the result drapes or runs. Weighing makes the question disappear entirely: the grams do not change when you sift, so weigh the sugar first and then push it through the sieve purely to break up lumps before whisking.
Are powdered, confectioners’ and icing sugar the same thing?
Yes — three names for granulated sugar milled to a fine powder with a small amount of anti-caking starch, usually cornstarch, blended in so it does not cake in the box. Powdered and confectioners’ are the American names and icing sugar is the British one. US packaging is often marked 10X, which describes how fine the mill is rather than any difference in the sugar itself. They are interchangeable by weight, and any difference in a finished icing comes from the liquid and fat you add, not from the sugar name on the packet.
How many cups are in a 1 lb box of powdered sugar?
About 4 cups unsifted. A one-pound box is 454 grams and an unsifted cup is 113 grams, so 454 ÷ 113 comes to just over four. That is why so many American frosting recipes call for exactly 4 cups: the recipe is really asking you to use the whole box. A two-pound bag is therefore around 8 cups. Weighing straight from the box is faster and cleaner than four separate cup measures, and it avoids the fine dust that a measuring cup inevitably throws around the worktop.
Why does my powdered sugar clump, and should I sift it?
It clumps because it is hygroscopic: the very fine particles and the cornstarch blended with them pull moisture out of the air and stick together, which is worse in a humid kitchen or an opened bag. For anything you whisk smooth — royal icing, buttercream, glaze, a filling — sift first or the lumps will not dissolve and the finished icing will feel gritty. For dusting a cake or doughnuts, just push a spoonful through a fine sieve as you go. Sifting is about texture at least as much as about the weight.
Sources
Where the constants and formulas on this page come from. Each line names the figure it backs.
The published per-cup weight the page cites as a comparable for confectioners sugar.
Ingredient Weight Chart — King Arthur Baking
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