Convert Cups to Grams: Caster Sugar
Convert cups of caster sugar to grams with this complete reference table. 1 cup of caster sugar = 210g (USDA FoodData Central, spooned-and-leveled method). Use the table below for fractions from 1/8 cup up to 4 cups. For precision baking, weight measurements in grams are always more reliable than volume measurements in cups, because caster sugar density can vary by measuring technique.
Caster Sugar Cups to Grams Table
| Cups | Grams |
|---|---|
| 1/8 cup | 26.3g |
| 1/4 cup | 52.5g |
| 1/3 cup | 70g |
| 1/2 cup | 105g |
| 2/3 cup | 140g |
| 3/4 cup | 157.5g |
| 1 cup | 210g |
| 1 1/4 cups | 262.5g |
| 1 1/2 cups | 315g |
| 2 cups | 420g |
| 3 cups | 630g |
| 4 cups | 840g |
Based on USDA FoodData Central data (1 US cup = 240ml = 16 tablespoons = 48 teaspoons). Note: Caster sugar (superfine sugar) has finer crystals than regular granulated sugar. 1 cup = 210g. Dissolves faster than regular sugar — ideal for meringues, mousses, cold drinks. Common in UK/Australian recipes.
About Caster Sugar Density
The density of caster sugar determines how much it weighs per unit of volume. At 0.875g/ml, 1 US cup (240ml) of caster sugar weighs 210g under USDA standard conditions.
Volume measurements can vary by ±10–20% depending on technique (sifted vs. spooned vs. scooped). For consistent baking results, use a kitchen scale with gram measurements whenever possible. The USDA standard (spooned-and-leveled) is the reference point for all values on this page.
Frequently Asked Questions
How many grams is 1 cup of caster sugar?
1 cup of caster sugar weighs 210 grams (USDA FoodData Central, spooned-and-leveled method, 1 US cup = 240ml).
How many grams is 1/2 cup of caster sugar?
1/2 cup of caster sugar weighs 105 grams.
How many grams is 1/4 cup of caster sugar?
1/4 cup of caster sugar weighs 53 grams.
Does measuring technique affect the weight of caster sugar?
Yes. Sifted caster sugar can weigh up to 20% less than packed or scooped. The USDA standard (spooned-and-leveled) of 210g/cup is the most reliable baseline.