Powdered sugar in grams, before and after the sieve

Spooned from the bag as it comes, powdered sugar weighs 113 grams to the US cup. Sift it first and the same cup holds 100. When an icing recipe says sifted, it is naming a 13 gram difference, which is why it bothers to say so.

Sifted or not: what the sieve takes out

A sieve breaks the lumps and leaves more air between the grains, so the same cup carries less sugar: 100 g against 113. Our own two figures say as much, since the volume did not change and the weight did. That is 13 grams, more than a tenth of the cup, decided by a step the recipe already told you to take.

Brown sugar swings the other way: you press it in and the cup gains. Here you break it up and the cup loses. The two are the same lesson from opposite ends, and the brown sugar master takes the packed side.

Powdered sugar conversions in full

Unsifted figures, following King Arthur's 113 gram cup. A cup of powdered sugar in grams comes from it, and two cups covers a larger batch. Sifting takes 13 g off any row below it.

Density used: 0.48 g per ml, unsifted.

Why we follow a round four ounces here

King Arthur's 113 g is 4 ounces on the nose, and a round imperial figure is usually a sign that someone chose a number rather than read one. On vegetable oil that same signature is why we set King Arthur aside. Here we follow it anyway, and the reason is the size of the stakes. The two authorities disagree by 7 g on an unsifted cup, 120 against 113, while the sieve moves that cup by 13 g, nearly twice as far. Picking between the charts is the small decision; picking up the sieve is the large one. American recipes are written to King Arthur, so we publish its figure and point you at the step that matters.

The chart we left out

One more source prints a metric cup of icing sugar, and we excluded it. Healthy Food Guide gives 210 g for the row while its own fractional columns work out to about 140 g for the same cup. A chart that disagrees with itself inside one line is not a reading we can weigh against the others, so it is absent from our data rather than averaged into it. The methodology page explains why a source that fails on a row we can check does not get trusted on rows we cannot.

Powdered sugar abroad

Edmonds weighs a 250 millilitre cup of icing sugar at 150 g and Australian Women's Weekly at 160. Kyoritsu weighs the 200 millilitre Japanese cup at 100 g, and Benricho has no powdered-sugar row, so the Japanese figure rests on one table.

Questions about powdered sugar weight

How many grams is a cup of powdered sugar?

113 g spooned from the bag unsifted, the King Arthur figure. Sift it first and the same cup holds 100 g, so the recipe's word matters more than the chart you read.

Does it matter if I sift powdered sugar?

To the weight, yes: 13 g a cup, 113 down to 100. Icing recipes ask for it because of the lumps rather than the grams, so the instruction stands whether or not you own a scale.

Is a teaspoon of powdered sugar sifted or unsifted?

The USDA does not say. It labels its cup and its tablespoon unsifted and leaves the 2.5 g teaspoon unqualified, so we print the figure and the gap in what is known rather than guess which state it meant.

Sources

King Arthur Baking for the 113 gram unsifted cup. USDA FoodData Central SR Legacy for the 120 gram unsifted cup, the 100 gram sifted cup, the 8 gram tablespoon and the 2.5 gram teaspoon. Edmonds and Australian Women's Weekly for the metric cup. Kyoritsu Foods for the 100 gram Japanese cup. Full citations on the sources page.