Rolled Oats — Grams & Cups Converter
1 cup of rolled oats (also called oats, porridge oats, old-fashioned oats) weighs about 90 g. So 100 g ≈ 1 1/8 cups, 200 g ≈ 2 1/4 cups, and 300 g ≈ 3 1/3 cups. Convert any amount between grams, cups, ounces, tablespoons and millilitres with the calculator below.
💡 Tip: Rolled oats are chewier than quick oats and swap 1:1 in most recipes, though quick oats absorb liquid faster and cook softer.
Cups to grams chart for rolled oats
| Cups | Grams | Ounces |
|---|---|---|
| 1/4 | 22.5 | 0.79 |
| 1/3 | 30 | 1.06 |
| 1/2 | 45 | 1.59 |
| 2/3 | 60 | 2.12 |
| 3/4 | 67.5 | 2.38 |
| 1 | 90 | 3.17 |
| 1 1/2 | 135 | 4.76 |
| 2 | 180 | 6.35 |
| 3 | 270 | 9.52 |
Grams to cups chart for rolled oats
| Grams | Cups | Ounces |
|---|---|---|
| 10 | 1/8 | 0.35 |
| 25 | 1/4 | 0.88 |
| 50 | 1/2 | 1.76 |
| 75 | 7/8 | 2.65 |
| 100 | 1 1/8 | 3.53 |
| 125 | 1 3/8 | 4.41 |
| 150 | 1 2/3 | 5.29 |
| 200 | 2 1/4 | 7.05 |
| 250 | 2 3/4 | 8.82 |
| 300 | 3 1/3 | 10.6 |
| 500 | 5 1/2 | 17.6 |
Spoon reference: 1 tablespoon ≈ 5.63 g, 1 teaspoon ≈ 1.88 g.
Why oats weigh so little (and serving sizes)
Rolled oats are airy flakes, so a cup is only about 90g — one of the lightest dry ingredients in the kitchen. That makes weighing especially worthwhile, since a loosely or firmly filled cup can vary a lot. A standard dry serving is 40g, roughly ½ cup.
Rolled and quick oats weigh the same per cup and swap 1:1; quick oats simply cook faster and give a softer texture. Steel-cut oats are denser and are not a cup-for-cup substitute, so convert those by weight.
Frequently asked questions
- How many grams is 1 cup of rolled oats?
- 1 US cup of rolled oats weighs about 90 grams (3.17 ounces).
- How many cups is 100g of rolled oats?
- 100 grams of rolled oats is about 1 1/8 cups.
- How many cups is 200g of rolled oats?
- 200 grams of rolled oats is about 2 1/4 cups.
- How many cups is 250g of rolled oats?
- 250 grams of rolled oats is about 2 3/4 cups.
- How many cups is 300g of rolled oats?
- 300 grams of rolled oats is about 3 1/3 cups.
- How many cups is 500g of rolled oats?
- 500 grams of rolled oats is about 5 1/2 cups.
- How many grams is ½ cup of rolled oats?
- Half a US cup of rolled oats is about 45 grams.
- How much does 1 cup of rolled oats weigh?
- 1 cup of rolled oats weighs about 90 grams, or roughly 3.17 ounces.
- How many grams in a tablespoon of rolled oats?
- About 5.63 grams per tablespoon (and roughly 1.88 g per teaspoon).
- Why do my numbers differ slightly?
- Density changes with how the rolled oats is packed, sifted or measured. For precise baking, weigh with a scale instead of using cups.
- How many grams is 1 cup of rolled oats?
- 1 cup of rolled oats is about 90g (3.2 ounces), and 2 cups is 180g. Oats are light because the flakes trap a lot of air.
- How many grams is a serving of oats?
- A typical dry serving is 40g, which is about ½ cup of rolled oats.
- Why is a cup of oats so light?
- Rolled oats are flattened flakes that stack loosely with lots of air between them, so a cup holds only about 90g — far less than a cup of flour or sugar.
- Do rolled oats and quick oats weigh the same?
- Yes, both are about 90g per cup. Quick oats are just rolled thinner and cut smaller, so they cook faster and absorb liquid quicker, but the weight per cup is the same.
- How many cups is 50g of oats?
- 50g of rolled oats is a generous ½ cup (about 0.56 cups).