One-Third Cup of Rolled Oats in Grams

1/3 cup of rolled oats weighs 30g (1.06 oz, 80ml) according to USDA FoodData Central (1 cup rolled oats = 90g, spooned and leveled method). 1/3 cup = 0.3333 of a full cup (240ml). See the full conversion table below for all amounts from 1 tablespoon to 3 cups.

1/3 Cup
30g
1.06 oz
1/3 Cup → ml
80ml
0.375 g/ml density
1 cup reference
90g
USDA standard

Rolled Oats Cup-to-Gram Conversion Table

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

AmountGrams
1 tbsp5.63g
2 tbsp11.25g
1/8 cup11.25g
1/4 cup22.5g
1/3 cupthis page30g
1/2 cup45g
2/3 cup60g
3/4 cup67.5g
1 cup90g
1 1/4 cups112.5g
1 1/2 cups135g
1 3/4 cups157.5g
2 cups180g
2 1/2 cups225g
3 cups270g

Source: USDA FoodData Central (FDC ID: 20036). 1 US cup = 240ml. Values use spooned-and-leveled method.

1/3 Cup of Different Ingredients — Weight Comparison

1/3 cup of different ingredients varies widely in weight because each has a different density. This matters when substituting ingredients in recipes.

Ingredient1/3 Cup (g)
Rolled Oatscurrent30g
Oat Flour30.67g
Steel-Cut Oats53.33g

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

Measuring Rolled Oats Accurately

Why weight matters: 1/3 cup of rolled oats can weigh anywhere from 26g to 36g depending on how you measure it. The USDA standard is 30g (spooned and leveled). Scooping directly from the container can add 10–20% extra weight, which affects recipe results — especially in baking.

About rolled oats density: Rolled oats (old-fashioned oats) are flat and large. 1 cup = 90g. Quick oats are cut smaller — same weight per cup. Steel-cut oats are different: 1 cup = 160g (denser, unrolled). Used for granola, cookies, overnight oats.

Spoon & Level
30g
USDA standard — most accurate for volume cups
Scooped (packed)
~35g
10–20% heavier — avoid for precision baking
Kitchen Scale
30g
Most reliable — eliminates technique variation

About 1/3 Cup as a Measurement

1/3 cup = 5 tablespoons + 1 teaspoon = 80ml. This unusual fraction appears in recipes that scale for 2 servings from a 3-serving base. It cannot be made from combining standard 1/4 and 1/8 cup measures without error.

One-third cup is common in yogurt parfait recipes, small-batch granola bars, and single-layer cake recipes scaled for 2 servings. It is exactly 80ml in metric volume.

Frequently Asked Questions

How many grams is 1/3 cup of rolled oats?

1/3 cup of rolled oats weighs 30 grams (1.06 oz, 80ml). Based on USDA FoodData Central: 1 cup rolled oats = 90g, so 1/3 cup = 90 × 0.333 = 30g.

Is 1/3 cup of rolled oats the same weight every time?

The weight can vary slightly depending on measuring technique. Spooned and leveled gives 30g. Scooped (packed) can be 10–20% heavier. Sifted gives a lighter weight. The USDA standard (spooned and leveled) of 30g is the most reliable baseline for recipes.

How do I accurately measure 1/3 cup of rolled oats?

For accuracy, use a kitchen scale and weigh 30g of rolled oats. If using measuring cups, spoon the rolled oats lightly into a 1/3 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 1/3 cup of rolled oats compare to other ingredients?

1/3 cup of different ingredients varies significantly: Rolled Oats = 30g, Oat Flour = 30.67g, Steel-Cut Oats = 53.33g. This is because each ingredient has a different density.

Other Amounts for Rolled Oats

Data source: USDA FoodData Central SR Legacy (FDC ID: 20036). View original USDA record

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