1 cup rolled oats in grams
Quick answer
1 US cup of rolled oats ≈ 90 g.
Grams
90
Cups → grams table
| Cups | Grams |
|---|---|
| 0.25 | 22.5 |
| 0.333 | 30 |
| 0.5 | 45 |
| 0.75 | 67.5 |
| 1 | 90 |
| 1.5 | 135 |
| 2 | 180 |
| 3 | 270 |
Smaller measures of oats
Recipes rarely call for a round cup. Since a US cup is 16 tablespoons (48 teaspoons), the same 90 g/cup density gives:
| Measure | In cups | Grams |
|---|---|---|
| 1 teaspoon | 1/48 | 1.9 g |
| 1 tablespoon | 1/16 | 5.6 g |
| 1/4 cup | 0.25 | 22.5 g |
| 1/3 cup | 0.333 | 30 g |
| 1/2 cup | 0.5 | 45 g |
Why cup measurements drift
A cup measures volume, not weight, so the gram figure depends on how densely the oats sits in the cup. Two people measuring "one cup" from the same bag can differ by 10–20% — which is why baking recipes that matter tend to be written in grams.
- Scooping compacts. Dipping the cup into the bag presses the contents down and packs in more than the recipe intended. Spooning it in loosely and levelling the top with a straight edge is closer to the published figure.
- Settling matters. Anything that has been sitting in a bag or jar has compacted on its own. Loosening it first gives a more repeatable measure.
- Cup size is not universal. A US customary cup is about 240 ml, a metric cup is 250 ml, and an Imperial cup is roughly 284 ml. The 90 g figure above is per US cup — using a metric cup gives about 94 g instead.
- Humidity and brand vary. Densities are culinary averages, not lab constants. When the ratio really matters, weigh it.
Frequently asked questions
How many grams is 1 cup of rolled oats?
About 90 grams per US cup. Densities are culinary averages — weigh when precision matters.
How many grams in a cup of oats?
A cup of oats is about 90 grams. Use the calculator above for other amounts, like 2 or 3 cups.