Short answer: 100 g of powdered sugar is 0.88 cups (about 7/8 cup). One cup of powdered sugar weighs 113 g (spooned and levelled, King Arthur Baking), so 100 g ÷ 113 g per cup = 0.88 cups. The rest of this guide is built for cooks who want more than a single number: a grams-to-cups table from 25 g to 500 g, a cups-to-grams table for going the other way, worked examples, and practical advice on measuring powdered sugar well without a scale.
About powdered sugar
Granulated sugar ground to a fine powder with a little cornstarch. Icings, glazes, dusting and buttercream. Airtight container, cool and dry, indefinitely. That background matters for converting, because how an ingredient is stored and handled changes how it packs into a cup. A bag that has sat open in a humid kitchen weighs differently from a freshly opened one, and a cook who scoops straight from the bag will pack more into the cup than a cook who spoons it in lightly. Knowing the ingredient helps you judge when the table figure is close enough and when to reach for the scale instead. For sweetening and baking, the cup weight of 113 g is the anchor: every number on this page is that figure divided or multiplied, never a separate guess.
100 g of powdered sugar in cups — conversion table
One cup of powdered sugar weighs 113 g (spooned and levelled, King Arthur Baking). Divide any weight in grams by 113 to get cups. The table below does that division for the weights cooks most often meet, from a small 25 g spoonful up to 500 g. All cup figures are approximate.
| Grams | Cups (approx.) | Nearest kitchen measure |
|---|---|---|
| 25 g | 0.22 | about 1/4 cups |
| 50 g | 0.44 | about 1/2 cups |
| 75 g | 0.66 | about 2/3 cups |
| 100 g | 0.88 | about 7/8 cups <-- this page |
| 125 g | 1.11 | about 1 1/8 cups |
| 150 g | 1.33 | about 1 1/3 cups |
| 200 g | 1.77 | about 1 3/4 cups |
| 250 g | 2.21 | about 2 1/4 cups |
| 300 g | 2.65 | about 2 2/3 cups |
| 400 g | 3.54 | about 3 1/2 cups |
| 500 g | 4.42 | about 4 3/8 cups |
Two things are worth noticing in that table. First, the headline row is the one this page is built around: 100 g is 0.88 cups. Second, the relationship is linear, so doubling the grams doubles the cups and halving the grams halves them. That linearity is what makes the table safe to interpolate: if your recipe calls for 175 g, the answer sits halfway between the 150 g and 200 g rows.
Cups of powdered sugar back to grams
Sometimes the recipe is written in cups and the scale is the only tool on the bench. Multiply the cups by 113 g to get grams.
| Cups | Grams (approx.) |
|---|---|
| 1/4 cup | 28 g |
| 1/3 cup | 38 g |
| 1/2 cup | 56 g |
| 2/3 cup | 75 g |
| 3/4 cup | 85 g |
| 1 cup | 113 g |
| 1 1/2 cups | 170 g |
| 2 cups | 226 g |
That reverse table is the one to use when a recipe says “one cup of powdered sugar” and you would rather weigh it. Weighing removes the packing question entirely, which is why most professional bakers and many recipe developers now write grams first and cups second.
Worked examples
Halving or doubling a recipe
Halving a recipe that uses 0.75 cups of powdered sugar means weighing 85 g, which is 0.75 × 113 g. Doubling works the same way in reverse: twice the cups is twice the grams. Scaling by weight instead of by cup keeps the proportions honest, because a cup measured twice is rarely the same cup twice, while grams on a scale are the same every time.
Measuring without a scale
Without a scale, convert the headline amount into tablespoons: 0.88 cups × 16 tablespoons per cup = 14.2 tablespoons. Spoon the powdered sugar into a tablespoon measure, level each spoonful, and count 14 spoonfuls for a close approximation of 100 g. Tablespoons are smaller units, so the packing error on each spoonful partly averages out, though a scale is still more accurate for baking.
Adjusting a recipe that went wrong
If a previous batch came out too dry or too dense, the cup conversion is a good place to look. A cook who scooped powdered sugar straight from the bag may have used well over 113 g per cup, so a recipe that asked for 2.5 cups could have contained 325 g or more instead of 282 g. Weighing the next batch at 282 g for 2.5 cups is the simplest fix, and it costs nothing but a minute on the scale.
Method and source
The cup weight used on this page is 113 g for one US cup of powdered sugar, measured spooned and levelled, from King Arthur Baking. The method matters as much as the number. Spooned and levelled means the ingredient is transferred into the cup in the way the source describes, then levelled with a straight edge, and any other technique will give a different weight. A cook who scoops directly from the bag compresses the ingredient and can add a tenth or more to the weight, while a cook who sifts first adds air and takes weight away. That is why two honest sources can disagree about a cup weight without either being wrong: they measured differently. King Arthur lists 113 g unsifted; sifted powdered sugar is about 100 g per cup because sifting adds air. This page uses the primary value stated above, and every table and example follows from it, so the numbers are internally consistent even where other sources quote a slightly different cup weight.
All results on this page are approximate. Use them confidently for everyday cooking, and verify with a kitchen scale when the dish depends on precision, when you are scaling a recipe up for a crowd, or when you are developing a recipe other people will follow. A scale costs little, lasts for years, and removes the single biggest source of variation in cup conversions.
Common mistakes and how to fix them
The most common mistake with powdered sugar is packing the cup. Scooping from the bag, tapping the cup, or pressing the ingredient down all add weight, and the recipe then contains more powdered sugar than the developer intended. The fix is to spoon it in and level it, or better still to weigh it. The second mistake is using the wrong cup: a coffee mug is not a measuring cup, and a liquid jug is not a dry measure, so keep a proper set of dry cups and a jug with a spout for liquids. The third mistake is converting a weight for a different ingredient by mistake, because cup weights vary enormously between ingredients and a cup of one thing can weigh half as much as a cup of another. Always check the ingredient name at the top of the table before you use it. If a bake has already gone wrong, weigh the ingredient next time before changing anything else, because the conversion is the most likely culprit and the easiest to rule out.
Frequently asked questions
How many cups is the headline amount?
Use the division on this page: the headline weight divided by 113 g per cup. That is the figure in the first paragraph, rounded to two decimals, and it is approximate.
Should I weigh or measure in cups?
Weigh whenever you can. A scale removes the packing and spooning variables entirely, and most modern recipes list grams for exactly that reason. Cups are fine for forgiving dishes such as soups and stir-fries, but for baking, weighing is the difference between a recipe that works every time and one that works sometimes.
How do I measure powdered sugar in cups without a scale?
Use the spooned and levelled method from King Arthur Baking and level the top with a straight edge. For dry ingredients, spoon into the cup rather than scooping from the bag, and for liquids, set the jug on a flat surface and read it at eye level. Then check the result against the tables on this page.
Can I use this conversion for a different brand?
Yes, as a starting point. Brands vary slightly in grind, moisture, and packing, so a cup of one brand may weigh a gram or two more or less than another. If your bake is sensitive, weigh the first batch and note your own brand's figure for next time.
Does temperature change the conversion?
For dry powdered sugar the effect is small, but for fats and liquids it matters. A solid fat packs differently from a melted one, and a cold liquid is slightly denser than a warm one. Measure fats in the state the recipe expects, and weigh them when the amount is large.