CupsToGrams kitchen card
1 US cup = 240 ml, 1 tablespoon = 15 ml, 1 teaspoon = 5 ml. Figures verified 5 August 2026. https://cupsngrams.com/rolled-oats
Rolled Oats: Cups to Grams
Also called porridge oats or old fashioned oats.
One US cup (240 ml) of rolled oats weighs 90 grams; half a cup weighs 45 grams. A quarter cup is 22.5 grams, a tablespoon is 5.63 grams and a teaspoon is 1.88 grams. These numbers are for rolled oats only, because a cup measures volume, not weight.
90 g
1 cup of rolled oats = 90 g (US legal cup, 240 ml)
1 cup of rolled oats = 90 g (US legal cup, 240 ml)
Based on rolled oats at 90 g per US cup.
CupsToGrams, cupsngrams.com
Baking from a UK, Australian or New Zealand recipe? Their cup is not the American one. Pick the standard your recipe assumes and every cup figure follows it.
Rolled Oats conversion table
| Cups | Cups (decimal) | Grams | Tablespoons | Millilitres | Ounces (weight) |
|---|---|---|---|---|---|
| 1/8 cup | 0.125 | 11.3 g | 2 tbsp | 30 ml | 0.397 oz |
| 1/4 cup | 0.25 | 22.5 g | 4 tbsp | 60 ml | 0.794 oz |
| 1/3 cup | 0.33 | 30 g | 5.33 tbsp | 80 ml | 1.06 oz |
| 1/2 cup | 0.5 | 45 g | 8 tbsp | 120 ml | 1.59 oz |
| 2/3 cup | 0.67 | 60 g | 10.7 tbsp | 160 ml | 2.12 oz |
| 3/4 cup | 0.75 | 67.5 g | 12 tbsp | 180 ml | 2.38 oz |
| 1 cup | 1 | 90 g | 16 tbsp | 240 ml | 3.17 oz |
| 1 1/4 cups | 1.25 | 113 g | 20 tbsp | 300 ml | 3.97 oz |
| 1 1/3 cups | 1.33 | 120 g | 21.3 tbsp | 320 ml | 4.23 oz |
| 1 1/2 cups | 1.5 | 135 g | 24 tbsp | 360 ml | 4.76 oz |
| 1 2/3 cups | 1.67 | 150 g | 26.7 tbsp | 400 ml | 5.29 oz |
| 1 3/4 cups | 1.75 | 158 g | 28 tbsp | 420 ml | 5.56 oz |
| 2 cups | 2 | 180 g | 32 tbsp | 480 ml | 6.35 oz |
| 2 1/4 cups | 2.25 | 203 g | 36 tbsp | 540 ml | 7.14 oz |
| 2 1/2 cups | 2.5 | 225 g | 40 tbsp | 600 ml | 7.94 oz |
| 3 cups | 3 | 270 g | 48 tbsp | 720 ml | 9.52 oz |
| 3 2/3 cups | 3.67 | 330 g | 58.7 tbsp | 880 ml | 11.6 oz |
Ounces here are ounces of weight (1 oz = 28.35 g), not fluid ounces. One US cup is 8 fluid ounces of volume whatever is in it, but what it weighs in ounces depends on the ingredient: a cup of rolled oats weighs about 3.17 oz. Why these two are not the same. Decimals for thirds are rounded (1/3 cup is 0.333 cups), and each linked amount opens a page comparing every ingredient at that measure.
Cite this: CupsToGrams, "Rolled Oats: Cups to Grams", https://cupsngrams.com/rolled-oats, figures verified . The data is free to reuse under CC BY 4.0 with a link back to this page.
About measuring rolled oats
Rolled oats are flat, light flakes with plenty of air between them, so one US cup weighs only about 90 grams. Because the flakes settle, a cup you scoop straight after opening the bag can differ from one measured after the oats have compacted. For porridge the exact weight rarely matters, but in flapjacks, granola and oat cookies the ratio of oats to fat and sugar shapes the texture, so weighing helps.
Oats settle over time, so a fresh scoop and a settled one differ. Weigh for baking recipes.
How many grams is a cup of rolled oats?
One US cup (240 ml) of rolled oats weighs about 90 grams. Because a cup measures volume rather than weight, that figure is specific to rolled oats and does not transfer to any other ingredient: the same cup holds 125 grams of all-purpose flour and 340 grams of honey.
- 1/4 cup of rolled oats is about 23 grams
- 1/3 cup of rolled oats is about 30 grams
- 1/2 cup of rolled oats is about 45 grams
- 2/3 cup of rolled oats is about 60 grams
- 3/4 cup of rolled oats is about 68 grams
- 1 1/2 cups of rolled oats is about 135 grams
- 2 cups of rolled oats is about 180 grams
- 3 cups of rolled oats is about 270 grams
Working the other way round, 100 grams of rolled oats is about 1.11 cups, and 500 grams is about 5.56 cups.
Does it matter which cup my recipe means?
It does, though less than the ingredient itself. This page uses the US legal cup of 240 ml. An Australian metric cup is 250 ml, so a metric cup of rolled oats comes to about 94 grams, and the old British imperial cup of 284.1 ml holds about 107 grams. See cup sizes by country for every standard side by side.
Frequently asked questions
How many grams is 1 cup of rolled oats?
One US cup of rolled oats is about 90 grams. The flat flakes hold a lot of air, so oats are light for their volume.
Are quick oats the same weight as rolled oats?
Roughly. Quick oats are cut smaller and pack a little denser, so a cup can run slightly heavier, but 90 grams is a good working figure.
Does weighing oats matter for porridge?
Less so. For porridge you can eyeball it, but for granola, flapjacks and cookies the oats to fat ratio matters, so weighing pays off.
What else is rolled oats called?
Rolled oats is also called porridge oats or old fashioned oats. This site treats these names as the same product, so the figures on this page apply to all of them: one US cup weighs 90 grams.
Where this figure comes from
| Reference | Grams per US cup | Notes |
|---|---|---|
| King Arthur Baking ingredient weight chart | 89 g | Old-fashioned rolled oats, loose in the cup. Quick oats pack a little denser. |
| This page | 90 g | The figure the converter above uses |
This site prints 90 grams against King Arthur's 89. That is a one gram difference on a cup, well inside the variation you get from how loosely the oats sit, and the two figures should be read as the same number.
Published figures for the same ingredient vary between references anyway, because how an ingredient is packed changes what a cup of it weighs. Treat any cup figure as accurate to within a few percent, and weigh on a scale when a recipe is sensitive. Our full approach is on the methodology page.
Figures last verified . Compiled by the CupsToGrams editorial team at FusionStudios. Spotted a value that looks off? Tell us.