Two-Thirds Cup of Caster Sugar in Grams

2/3 cup of caster sugar weighs 140g (4.94 oz, 160ml) according to USDA FoodData Central (1 cup caster sugar = 210g, spooned and leveled method). 2/3 cup = 0.6667 of a full cup (240ml). See the full conversion table below for all amounts from 1 tablespoon to 3 cups.

2/3 Cup
140g
4.94 oz
2/3 Cup → ml
160ml
0.875 g/ml density
1 cup reference
210g
USDA standard

Caster Sugar Cup-to-Gram Conversion Table

Full range from 1 tablespoon to 3 cups. The highlighted row shows 2/3 cup.

AmountGrams
1 tbsp13.13g
2 tbsp26.25g
1/8 cup26.25g
1/4 cup52.5g
1/3 cup70g
1/2 cup105g
2/3 cupthis page140g
3/4 cup157.5g
1 cup210g
1 1/4 cups262.5g
1 1/2 cups315g
1 3/4 cups367.5g
2 cups420g
2 1/2 cups525g
3 cups630g

Source: USDA FoodData Central (FDC ID: 19335). 1 US cup = 240ml. Values use spooned-and-leveled method.

2/3 Cup of Different Ingredients — Weight Comparison

2/3 cup of different ingredients varies widely in weight because each has a different density. This matters when substituting ingredients in recipes.

Ingredient2/3 Cup (g)
Powdered Sugar80g
Granulated Sugar133.33g
Caster Sugarcurrent140g
Brown Sugar (packed)146.67g

All values use USDA FoodData Central spooned-and-leveled method. Click any ingredient to see its full conversion table.

Measuring Caster Sugar Accurately

Why weight matters: 2/3 cup of caster sugar can weigh anywhere from 119g to 168g depending on how you measure it. The USDA standard is 140g (spooned and leveled). Scooping directly from the container can add 10–20% extra weight, which affects recipe results — especially in baking.

About caster sugar density: 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.

Spoon & Level
140g
USDA standard — most accurate for volume cups
Scooped (packed)
~161g
10–20% heavier — avoid for precision baking
Kitchen Scale
140g
Most reliable — eliminates technique variation

About 2/3 Cup as a Measurement

2/3 cup = 10 tablespoons + 2 teaspoons = 160ml. This measure appears when scaling up 1/3 cup recipes by doubling. Use two 1/3-cup measures for accuracy, as 2/3 cup sets are less common.

Two-thirds cup is often seen in oatmeal cookie recipes, breakfast grain bowls, and rice cooker recipes for 2 servings. It equals exactly 160ml or approximately 5.4 fluid ounces.

Frequently Asked Questions

How many grams is 2/3 cup of caster sugar?

2/3 cup of caster sugar weighs 140 grams (4.94 oz, 160ml). Based on USDA FoodData Central: 1 cup caster sugar = 210g, so 2/3 cup = 210 × 0.667 = 140g.

Is 2/3 cup of caster sugar the same weight every time?

The weight can vary slightly depending on measuring technique. Spooned and leveled gives 140g. Scooped (packed) can be 10–20% heavier. Sifted gives a lighter weight. The USDA standard (spooned and leveled) of 140g is the most reliable baseline for recipes.

How do I accurately measure 2/3 cup of caster sugar?

For accuracy, use a kitchen scale and weigh 140g of caster sugar. If using measuring cups, spoon the caster sugar lightly into a 2/3 Cup measuring cup and level off the top with a straight edge. Avoid scooping directly from the container, which compacts the ingredient and adds extra weight.

How does 2/3 cup of caster sugar compare to other ingredients?

2/3 cup of different ingredients varies significantly: Powdered Sugar = 80g, Granulated Sugar = 133.33g, Caster Sugar = 140g. This is because each ingredient has a different density.

Other Amounts for Caster Sugar

Data source: USDA FoodData Central SR Legacy (FDC ID: 19335). View original USDA record

More Conversion Charts