How Many Grams in a Cup of Rolled Oats?
One cup of rolled oats weighs 99 grams — but “oats” covers three different cups: rolled oats at 99 grams, quick oats at 90, and steel-cut oats at 176. They are not interchangeable by volume. Below are the conversion tables for rolled, old-fashioned oats, a converter for any amount, and how to measure them loose, as the number assumes.
Convert rolled oats instantly
This converter uses the same chef-reviewed database as our Cups to Grams converter for all 128 ingredients. Weights assume a US cup of 236.588 ml; see our methodology and sources.
Cups to grams: rolled oats
| Cups | Grams |
|---|---|
| ¼ cup | 25 g |
| ⅓ cup | 33 g |
| ½ cup | 50 g |
| ⅔ cup | 66 g |
| ¾ cup | 74 g |
| 1 cup | 99 g |
| 1½ cups | 149 g |
| 2 cups | 198 g |
| 3 cups | 297 g |
| Measure | Grams |
|---|---|
| 1 tablespoon | 6.2 g |
| 1 teaspoon | 2.06 g |
| 1 cup in ounces | 3.5 oz |
Grams to cups: rolled oats
| Grams | Cups (decimal) | Cups (fraction) |
|---|---|---|
| 50 g | 0.51 cups | ½ cups |
| 100 g | 1.01 cups | 1 cup |
| 125 g | 1.26 cups | 1 ¼ cups |
| 150 g | 1.52 cups | 1 ½ cups |
| 200 g | 2.02 cups | 2 cups |
| 250 g | 2.53 cups | 2 ½ cups |
| 300 g | 3.03 cups | 3 cups |
| 400 g | 4.04 cups | 4 cups |
| 500 g | 5.05 cups | 5 cups |
Working with more than one ingredient? The grams in a cup chart puts 40 ingredients in one table, and the Whole Recipe Converter converts a full ingredient list in a single paste.
How to measure rolled oats properly
Fill the cup loosely and level it. Rolled oats compress: press them down to “fit more in” and the cup climbs from 99 grams towards 120. Spoon or pour them in, shake the cup once to settle — not pack — and level the top.
Check which oat the recipe means. Rolled (old-fashioned) oats are the default in baking. Quick oats are cut finer and weigh 90 grams a cup; steel-cut oats are chopped groats at 176 grams a cup, and they need far longer cooking. A cup-for-cup swap between them changes both weight and texture.
Weigh oats and liquid together for porridge. Oats absorb variable amounts of liquid depending on age and brand, which is why porridge consistency wanders. A reliable starting ratio is equal weights of rolled oats and liquid — 99 grams of each per cup — adjusted after the first bowl, not guessed every morning.
Frequently asked questions
How many grams are in a cup of rolled oats?
99 grams, for rolled (old-fashioned) oats poured or spooned loosely into the cup and levelled. The same volume of quick oats weighs 90 grams and steel-cut oats 176 grams, so check which oat your recipe means before using the figure.
How many grams are in half a cup of rolled oats?
50 grams (half of 99, rounded). Half a cup is the standard single serving for porridge and overnight oats; weighed with an equal 50 grams of milk or water, it gives a consistent bowl every time.
Can I substitute steel-cut oats for rolled oats by the cup?
No. A cup of steel-cut oats weighs 176 grams against rolled oats' 99 — nearly double the oats, needing far more liquid and far longer cooking. If a recipe gives grams, the swap is possible with adjusted liquid and time; by volume it fails both ways.