Rolled Oats:
Grams to Cups
By Stefan Ulrich · Last updated
Rolled oats (old-fashioned oats) weigh 90 grams per cup — noticeably lighter than most flours because the flattened flakes have significant air space between them. This is one of the more generous measurements in baking: you get a lot of volume for your gram.
How much Rolled Oats weighs at each cup measure.
Convert Rolled Oats
1 cup = 90 grams
= — grams
= — cups
Quick reference
Measurement Table
| Cups | Grams | Ounces |
|---|---|---|
| 1 tsp | 2 g | 0.07 oz |
| 1 tbsp | 6 g | 0.21 oz |
| ⅛ cup | 11 g | 0.39 oz |
| ¼ cup | 23 g | 0.81 oz |
| ⅓ cup | 30 g | 1.06 oz |
| ½ cup | 45 g | 1.59 oz |
| ⅔ cup | 60 g | 2.12 oz |
| ¾ cup | 68 g | 2.40 oz |
| 1 cup | 90 g | 3.17 oz |
| 1¼ cups | 113 g | 3.99 oz |
| 1½ cups | 135 g | 4.76 oz |
| 2 cups | 180 g | 6.35 oz |
| 3 cups | 270 g | 9.52 oz |
About Rolled Oats
Old-fashioned rolled oats and quick oats share the same weight: approximately 90 g/cup. The difference is in how they're processed: quick oats are cut into smaller pieces before rolling, which is why they cook faster and have a smoother texture in baked goods. Instant oats are pre-cooked and dried, making them even more tender — they weigh about 80–85 g/cup because they're puffier.
Steel-cut oats are not rolled, so they're denser: approximately 175 g/cup. They cannot be substituted 1:1 for rolled oats in baked goods.
Oat flour — made by grinding rolled oats — weighs 100–104 g/cup, similar to cake flour. You can make it at home in a blender. One cup of rolled oats produces approximately ¾ cup of oat flour (90 g oats → about 90 g oat flour).
For oatmeal cookies, most recipes use old-fashioned oats. Quick oats work but produce a less chewy result. Instant oats should be avoided in baking — they turn mushy.
Tips for measuring Rolled Oats
- Old-fashioned and quick oats: ~90 g/cup. Steel-cut: ~175 g/cup (much denser).
- 1 cup rolled oats ≈ ¾ cup + 2 tbsp oat flour if grinding at home.
- Instant oats absorb more liquid — avoid them in cookies and bars.
- Toasting oats before measuring deepens flavor and has negligible weight effect.
Common mistakes
- Substituting steel-cut for rolled oats — they will not soften properly in most recipes
- Grinding old-fashioned oats and measuring as if they were rolled oats (denser)
Frequently Asked Questions
- How many grams in a cup of Rolled Oats?
- 1 cup of Rolled Oats weighs 90 grams — the standard used in most American recipes. Use the converter above for any other amount.
- How many grams is 1 tablespoon of Rolled Oats?
- 1 tablespoon of Rolled Oats weighs about 6 grams. The full table above lists every common cup fraction.
- What's the most common mistake when measuring Rolled Oats?
- Substituting steel-cut for rolled oats — they will not soften properly in most recipes. Weighing on a kitchen scale avoids it entirely.
- Should Rolled Oats be measured cooked or dry?
- These values are for dry, uncooked rolled Oats. Cooked weights differ greatly because of absorbed water.