Quick Answer
One US cup of rolled oats weighs about 90 grams. That works out to 5.63 g per tablespoon and 1.88 g per teaspoon. Old-fashioned rolled oats. Quick oats ~95 g; steel-cut ~100 g. Weights vary slightly by brand, moisture, and how tightly you pack - for precise baking, a kitchen scale beats volume measures.
Key Facts
- 1 cup rolled oats = 90 g
- 1 tablespoon = 5.63 g
- 1 teaspoon = 1.88 g
- 1/2 cup = 45 g
- Old-fashioned rolled oats. Quick oats ~95 g; steel-cut ~100 g.
- Values assume standard US measures (1 cup = 236.59 mL)
Frequently Asked Questions
How many grams in 1 cup of rolled oats?
About 90 grams, scoop-and-level for dry ingredients. Old-fashioned rolled oats. Quick oats ~95 g; steel-cut ~100 g.
How many grams in a tablespoon of rolled oats?
One US tablespoon (15 mL) of rolled oats is about 5.63 grams. A teaspoon is 1.88 g.
Why does rolled oats weigh more (or less) than water?
Dry ingredients are weighed by how they pack into the cup volume. Rolled Oats has an apparent density of about 0.38 g/mL - lighter than water - depending on particle size and air gaps.
How many cups is 100 g of rolled oats?
100 g ÷ 90 g/cup ≈ 1.11 cups - about roughly 1.1 cups. The reverse table on this page covers 25-1000 g.
Should I weigh or measure by volume?
Weighing is more accurate - volume measures vary with how you scoop, pack, and level, and brands differ by 5-15%. For cookies and cakes where ratios matter, grams are the professional standard. The tables here convert either direction.