Conversion Table: Rolled Oats Cups to Grams
| Volume | Grams | Ounces |
|---|---|---|
| 1 tsp | 1.9 g | 0.07 oz |
| 1 tbsp | 5.6 g | 0.20 oz |
| ⅛ cup | 11.3 g | 0.40 oz |
| ¼ cup | 22.5 g | 0.79 oz |
| ⅓ cup | 30.0 g | 1.06 oz |
| ½ cup | 45.0 g | 1.59 oz |
| ⅔ cup | 60.0 g | 2.12 oz |
| ¾ cup | 67.5 g | 2.38 oz |
| 1 cup | 90.0 g | 3.17 oz |
| 2 cups | 180.0 g | 6.35 oz |
| 4 cups | 360.0 g | 12.70 oz |
How to Measure Rolled Oats
For grains, spoon into the cup and level. Do not pack.
For the most consistent results, use a kitchen scale. A cup measurement can vary by 15–30% depending on technique. Weighing eliminates that variable entirely.
Why the Gram Weight Varies by Ingredient
A cup is a measure of volume — how much space something occupies. Rolled Oats has a specific density (mass per unit volume) that determines how many grams fit in that space. The 90 g/cup value above is calibrated for the measuring method described (spoon and level where applicable).
Different ingredients have very different densities. Compare: water (237 g/cup), honey (340 g/cup), cake flour (96 g/cup). Using a single generic "cups to grams" ratio doesn't work — the ingredient must be specified.
Quick Converter
For more conversions, use our full cups to grams calculator which covers 89+ ingredients.
Frequently Asked Questions
How many grams is ½ cup of Rolled Oats?
45.0 grams (1.59 oz).
How many grams is ¼ cup of Rolled Oats?
22.5 grams (0.79 oz).
Is this weight for sifted or unsifted Rolled Oats?
Measurements use the standard technique for this ingredient. See the measuring note above.
Where does this weight come from?
Source: King Arthur Baking. See our methodology page for how we source and verify ingredient weights.