Grams in a Cup of Sugar: White, Brown, and Powdered Chart
Quick Summary
A cup is a unit of volume, and sugar — depending on its form — packs into that volume in three completely different ways. Moisture content, crystal size, molasses coating, mechanical pulverization, and trapped air all drive the actual gram count far away from any single fixed number.
The baseline weights bakers rely on: 200g per cup for white granulated sugar, 220g for firmly packed brown sugar, and 120g for sifted powdered sugar. Those numbers diverge fast once technique, humidity, and brand variation enter the picture — which is precisely why a kitchen scale is non-negotiable for precision work.
1. Granulated White Sugar: The Standard Weight
White granulated sugar is refined sucrose in a uniform crystalline form. The individual crystals are angular, free-flowing, and dry — meaning they settle into a cup with relatively predictable interstitial spacing between each grain.
That structural consistency makes white sugar the most stable of the three types by volume. Knowing how many grams in a cup of white sugar lands you consistently at 200g when spooned and leveled, though direct scooping from a dense bag can push that number up to 210–215g due to slight compaction at the base of the cup.
Cup manufacturing tolerances also matter. A 240ml US legal cup and an older 236ml US customary cup produce a measurable difference at scale. For anything beyond a casual kitchen batch, a digital scale and a tool like the BakeMetric Precision Kitchen Converter eliminate that variable entirely.
2. Brown Sugar: The Impact of Moisture and Compaction
Brown sugar is granulated white sugar with a controlled quantity of molasses reintroduced during processing. That molasses film coats every individual sucrose crystal with a hygroscopic layer of viscous liquid sugar — and that changes everything about how it behaves in a cup.
The sticky coating causes the crystals to bind together rather than flow freely. An unpacked, loosely spooned cup of light brown sugar can weigh as little as 170g. The same cup firmly packed — the method nearly all recipe developers specify — climbs to 220g. That is a 50g swing from a single cup, which is a catastrophic inaccuracy in any structured bake.
Dark brown sugar contains a higher molasses percentage than light brown, which makes it denser and stickier. In practice, a packed cup of dark brown sugar typically weighs 5–8g more than its light brown counterpart. When working with packed brown sugar cups to grams conversions, always note the variety the recipe developer used.
3. Powdered Sugar: Aeration and the Necessity of Sifting
Confectioners' sugar — also called icing sugar or 10X sugar — is produced by mechanically ball-milling granulated sugar to a superfine powder. To prevent caking during storage, roughly 3% cornstarch is blended in. The result is an extremely fine, low-density powder that traps air aggressively.
An unsifted cup of powdered sugar, scooped straight from the bag, can weigh up to 150g. After passing through a fine-mesh sieve, that same volume drops to approximately 120g. A 30g spread from sifting alone is not trivial — it represents a 25% mass variation that will make or break a buttercream or royal icing consistency.
The powdered sugar cup weight chart standard of 120g assumes the sifted state. Most professionally tested recipes default to this. If a recipe does not specify, sift anyway — it also breaks up any lumps that would otherwise survive mixing and appear as white specks in finished frostings.
Just as the approach for converting cups to grams for flour depends on technique and flour type, powdered sugar demands the same methodical awareness before a single gram hits the bowl.
4. The Ultimate Sugar Weight Conversion Chart
Use the table below as your definitive baking sugar weight reference. All values assume standard technique: white sugar spooned and leveled, brown sugar firmly packed, powdered sugar sifted before measuring.
| Sugar Type | 1 Cup | ¾ Cup | ½ Cup | ⅓ Cup | ¼ Cup | 1 Tablespoon |
|---|---|---|---|---|---|---|
| White Granulated Sugar | 200 g | 150 g | 100 g | 67 g | 50 g | 12 g |
| Light Brown Sugar (packed) | 220 g | 165 g | 110 g | 73 g | 55 g | 14 g |
| Dark Brown Sugar (packed) | 225 g | 169 g | 113 g | 75 g | 56 g | 14 g |
| Powdered Sugar (sifted) | 120 g | 90 g | 60 g | 40 g | 30 g | 8 g |
| Powdered Sugar (unsifted) | 150 g | 113 g | 75 g | 50 g | 38 g | 9 g |
| Caster / Superfine Sugar | 200 g | 150 g | 100 g | 67 g | 50 g | 12 g |
| Raw / Turbinado Sugar | 210 g | 158 g | 105 g | 70 g | 53 g | 13 g |
5. How Volumetric Inaccuracy Alters Recipe Chemistry
Sugar is hygroscopic — it actively draws moisture from the surrounding environment, including from other ingredients in the batter. When you overshoot the sugar weight in a cookie dough, that excess sugar pulls additional moisture from the eggs and butter, leading to a flatter, wider spread than the recipe intended.
Sugar also directly controls the Maillard browning reaction and caramelization onset temperature. Too much sugar in a cake batter can cause excessive browning on the exterior before the interior structure sets — leaving a dark crust and an underbaked center. These are not subtle failures; they are direct mechanical consequences of imprecise baking sugar weight.
Standardized cooking measurement histories, as tracked across global culinary measurement references, show that professional recipe development has shifted almost entirely to weight-based specifications precisely because these volume inconsistencies are well-documented and reproducible.
Once you convert a recipe to grams, those numbers are yours permanently. Drop the full ingredient list with exact gram weights into a SnapPad notepad directly in your browser — no app, no account, no risk of closing the tab and losing your work mid-session.