Powdered Sugar: Cups to Grams
Confectioners' sugar, icing sugar — same powder, same conversion, and one sifting caveat that matters.
Powdered sugar conversion table
| Cups | Grams | Ounces |
|---|
Sifted vs. unsifted — read the recipe carefully
The weight on this page, 113 g per cup, is King Arthur's figure for powdered sugar unsifted: spooned straight from the bag into the cup and levelled. Sifting changes the picture. It knocks lumps apart and folds air through the powder, so the same cup, filled with sifted sugar, holds noticeably less sugar.
Recipes signal which one they want with word order, and it is worth learning to spot:
- "1 cup sifted powdered sugar" — sift first, then measure the cup from the sifted pile.
- "1 cup powdered sugar, sifted" — measure the cup first (unsifted, the 113 g standard), then sift it into the bowl.
- Just "1 cup powdered sugar" — use the unsifted measure, 113 g.
This site deliberately does not publish a gram weight for a sifted cup: our source chart doesn't give one, and a sifted cup's weight depends heavily on how it was sifted and filled. When in doubt, weigh 113 g and sift it afterwards — you get the recipe's sugar amount with lump-free texture.
Why a cup of powder weighs barely half a cup of granulated
| Sugar | Grams per US cup |
|---|---|
| Powdered (confectioners') sugar, unsifted | 113 g |
| Granulated sugar | 198 g |
Source: King Arthur Baking Ingredient Weight Chart.
It is the same sugar in both rows. Grinding it to a powder makes the particles trap far more air, so a cup of powder is mostly air by volume. Two practical consequences: never substitute powdered for granulated (or the reverse) cup-for-cup in a recipe — you'd be off by 85 g per cup — and for glazes and frostings, where powdered sugar is the structure, weighing is the only way to get the same consistency twice.
Frequently asked questions
Are powdered sugar, confectioners' sugar and icing sugar the same thing?
Yes — three names for the same product: granulated sugar ground to a fine powder, usually with a little starch mixed in to stop it clumping. US recipes say powdered or confectioners'; UK and Commonwealth recipes usually say icing sugar. The conversion is the same: 113 g per cup, unsifted.
What is the difference between sifted and unsifted powdered sugar?
Sifting breaks up lumps and stirs air into the powder, so a cup filled with sifted sugar holds less sugar by weight than a cup of unsifted sugar. The King Arthur chart value used on this site — 113 g per cup — is for unsifted sugar, spooned into the cup. Follow the recipe's wording: "1 cup sifted powdered sugar" means sift, then measure; "1 cup powdered sugar, sifted" means measure, then sift.
Why does powdered sugar weigh so much less per cup than granulated?
113 g versus 198 g per cup on the King Arthur chart. The powder's fine particles trap a great deal of air, and much of the cup's volume is air rather than sugar. It is the same sugar — there is just far less of it in the cup.
Can I make powdered sugar from granulated sugar?
Yes: blitz granulated sugar in a clean spice grinder or high-speed blender until it turns to powder. Homemade powder packs differently from the commercial product, so if a recipe gives a gram weight, weigh your homemade powder to that weight instead of trusting the cup.
How many cups is 500 g of powdered sugar?
About 4.4 cups (500 ÷ 113). Use the converter on this page for exact amounts in either direction.
Data source: King Arthur Baking Ingredient Weight Chart (grams per US customary cup, 236.588 mL; other cup sizes scaled by volume ratio).