Cups of powdered sugar to ounces runs on one number, 4.2328754 ounces per cup. It is a measured property of this ingredient rather than a defined conversion, which is why a generic volume-to-weight tool cannot give you it.
Water is the yardstick: 1 mL of it weighs 1 g. Powdered sugar comes in at 0.50721 g per mL, or 50.72% of water, which is why a cup of it is 120 g rather than 236.6 g. Volume and weight only line up for water, and only in metric.
A cup of powdered sugar is 120 g when it is measured the standard way, but how it gets into the cup changes the answer: between about 108 g and 144 g covers the range from lightly spooned to firmly packed. That 20% spread is larger than most of the adjustments recipes fuss over, and it disappears entirely the moment the ingredient is weighed instead.
One cup of powdered sugar is 4.233 oz. US kitchen scales usually step in eighths of an ounce, which is 3.54 g — around 2.95% of a cup of this ingredient, so the scale is precise enough for a full cup and coarse for a spoonful. That is why recipes mix the two systems: ounces for the bulk, spoons for the small amounts.
How the figure is arrived at: Sifted. Scooped unsifted it runs 10 to 15% heavier because it clumps around the anti-caking starch.
The formula
cups- The amount of powdered sugar you are converting, in cups
4.23287543395- Ounces per cup for powdered sugar, from its density of 0.50721 g/mL
ounces- The equivalent quantity in ounces
How it works, step by step
- Enter the quantity in cups.
- It is multiplied by 4.23287543395, the ounces-per-cup figure for powdered sugar.
- The result appears in ounces, with a second reading in g beneath it.
- Use the measure table if you want a standard recipe quantity rather than a number you type in.
Worked examples
1/3 cup of powdered sugar in ounces
1/3 cup of powdered sugar weighs out at 1.41096 ounces. Divide 1.41096 by 4.2328754 and you get back to 1/3 cup, which is the quickest check that the factor is the right way up.
3/4 cup of powdered sugar in ounces
A recipe calling for 3/4 cup of powdered sugar needs 3.17466 ounces on the scale. The arithmetic is 0.75 × 4.2328754 = 3.1746566, and halving the recipe halves the weight to 1.58733 ounces.
3 cup of powdered sugar in ounces
3 cup of powdered sugar weighs out at 12.6986 ounces. Divide 12.6986 by 4.2328754 and you get back to 3 cup, which is the quickest check that the factor is the right way up.
How to read your score
Frequently asked questions
How many ounces are in 1 cup of powdered sugar?
One cup of powdered sugar is 4.2328754 ounces. Half that quantity is 2.11644 ounces and double it is 8.46575 ounces, so the figure scales straight up and down — there is no offset in this conversion, only the factor.
Why is a cup of powdered sugar not 236 g like water?
Because weight per cup depends on what is in the cup. Powdered sugar has a density of 0.50721 g per mL where water has 1.00, so a cup of it weighs 120 g rather than 236.6 g. That is a difference of 116.6 g per cup, and it is the reason a single volume-to-weight factor cannot be applied to every ingredient.
Does how I measure it change the weight?
Yes, and by more than most people expect. Handling changes the weight of a cup of powdered sugar by roughly 20% — about 12 g either side of 120 g — because sifted. Weighing removes the question entirely.
Is a fluid ounce of powdered sugar the same as an ounce?
No. A fluid ounce is a volume — one eighth of a US cup, 29.57 mL — and an ounce is a weight. One fluid ounce of powdered sugar weighs 0.5291 oz, so the two readings differ by 47.1%. They coincide only for something with the density of water, and then only roughly.
Is this a US cup or a metric cup?
US customary: 236.59 mL, which is the cup every US recipe means. A metric cup is 250 mL, so the same cup of powdered sugar would weigh 126.8 g instead of 120 g — 6.8 g more, or 5.67%. Australian and some European recipes use the metric cup, and the difference is large enough to matter in baking.
Do I need a scale for this, or will measuring cups do?
A scale, if the result matters. Volume measuring carries a spread of about 20% for powdered sugar — roughly 24 g on a 120 g cup — while a domestic scale is accurate to a gram or two. For anything where the ratio of ingredients drives the outcome, bread and pastry above all, weigh it.
How many cups of powdered sugar is 16 oz?
16 oz of powdered sugar is 3.7799 cups — 0.236246 cups to one ounce, so 16 × 0.236246 = 3.7799. Going that way is a division by 4.23288, or a multiplication by 0.236246 if you prefer.
Powdered sugar in cups and ounces
| Cups | Ounces | Unrounded |
|---|---|---|
| 1/8 cup | 0.529109 oz | 0.5291094292 |
| 1/4 cup | 1.05822 oz | 1.058218858 |
| 1/3 cup | 1.41096 oz | 1.410958478 |
| 1/2 cup | 2.11644 oz | 2.116437717 |
| 2/3 cup | 2.82192 oz | 2.821916956 |
| 3/4 cup | 3.17466 oz | 3.174656575 |
| 1 cup | 4.23288 oz | 4.232875434 |
| 1 1/2 cup | 6.34931 oz | 6.349313151 |
| 2 cup | 8.46575 oz | 8.465750868 |
| 3 cup | 12.6986 oz | 12.6986263 |
| 4 cup | 16.9315 oz | 16.93150174 |
Based on 120 g per cup of powdered sugar. One cup of powdered sugar is 4.2328754 ounces.
| Measure | Grams | Ounces | Millilitres |
|---|---|---|---|
| 1 cup | 120 g | 4.23 oz | 236.6 mL |
| 3/4 cup | 90 g | 3.17 oz | 177.4 mL |
| 2/3 cup | 80 g | 2.82 oz | 157.7 mL |
| 1/2 cup | 60 g | 2.12 oz | 118.3 mL |
| 1/3 cup | 40 g | 1.41 oz | 78.86 mL |
| 1/4 cup | 30 g | 1.06 oz | 59.15 mL |
| 1 tbsp | 7.5 g | 0.265 oz | 14.79 mL |
| 1 tsp | 2.5 g | 0.0882 oz | 4.929 mL |
US customary measures: 1 cup = 236.59 mL, 1 tbsp = 14.79 mL, 1 tsp = 4.93 mL.
| Ingredient | Grams per cup | Ounces per cup | Density (g/mL) |
|---|---|---|---|
| Cake flour | 114 g | 4.021 oz | 0.4818 |
| Whole wheat flour | 120 g | 4.233 oz | 0.5072 |
| Tapioca starch | 120 g | 4.233 oz | 0.5072 |
| Powdered sugar (this page) | 120 g | 4.233 oz | 0.5072 |
| All-purpose flour | 125 g | 4.409 oz | 0.5283 |
| Self-rising flour | 125 g | 4.409 oz | 0.5283 |
| Bread flour | 127 g | 4.48 oz | 0.5368 |
Ordered by weight. The spread across this group is why a single generic cups-to-grams factor cannot work.