Rolled Oats grams to cups
One US cup of rolled oats weighs about 80 grams.
Oat groats steamed and pressed flat. The large, irregular flakes stack badly and trap a great deal of air, making oats one of the lightest things in the cupboard by volume.
Convert Rolled Oats
Enter an amount to see the conversion.
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Based on g per cup. Approximate — density varies with packing and brand.
Rolled Oats conversion chart
Generated from 80 grams per cup.
| Grams | Cups | In the kitchen |
|---|---|---|
| 25 g | 0.31 | 1/4 cup + 1 tbsp |
| 50 g | 0.63 | 1/2 cup + 2 tbsp |
| 75 g | 0.94 | 3/4 cup + 3 tbsp |
| 100 g | 1.25 | 1 1/4 cups |
| 125 g | 1.56 | 1 1/2 cups + 1 tbsp |
| 150 g | 1.88 | 1 3/4 cups + 2 tbsp |
| 200 g | 2.5 | 2 1/2 cups |
| 250 g | 3.13 | 3 cups + 2 tbsp |
| 300 g | 3.75 | 3 3/4 cups |
| 400 g | 5 | 4 3/4 cups + 4 tbsp |
| 500 g | 6.25 | 6 1/4 cups |
| 750 g | 9.38 | 9 1/3 cups + 2 tsp |
| 1000 g | 12.5 | 12 1/2 cups |
Rolled Oats cups to grams
The other direction, for following a recipe written in cups with a scale on the counter.
| Cups | Weight | In ounces |
|---|---|---|
| 1/8 cup | 10 g | 0.4 oz |
| 1/4 cup | 20 g | 0.7 oz |
| 1/3 cup | 27 g | 0.9 oz |
| 1/2 cup | 40 g | 1.4 oz |
| 2/3 cup | 53 g | 1.9 oz |
| 3/4 cup | 60 g | 2.1 oz |
| 1 cup | 80 g | 2.8 oz |
| 1 1/2 cups | 120 g | 4.2 oz |
| 2 cups | 160 g | 5.6 oz |
Rolled Oats in tablespoons, teaspoons and millilitres
Cup fractions stop being useful below about a quarter of a cup. These are the measures to reach for when the amount is small.
1 US cup
80 g
1 tablespoon
5 g
1 teaspoon
1.7 g
100 millilitres
34 g
One US cup is 16 tablespoons or 48 teaspoons, whatever is in it — those two are volume measures, so no density is involved.
Measuring notes
Scoop lightly and do not shake the cup to settle them. Tapping oats down can add a quarter to the weight.
Where this figure comes from: USDA FoodData Central — Cereals, oats, regular and quick, not fortified, dry. Verified 17 August 2026.
Rolled Oats — common questions
How many cups is 100 grams?
It depends entirely on the ingredient. 100 grams of all-purpose flour is about 0.83 cups, but 100 grams of honey is only about 0.29 cups, because honey is far denser. Grams measure weight and cups measure volume, so there is no single conversion that works for everything.
Why do different converters give different answers?
Mostly because they assume different measuring techniques. Flour spooned gently into a cup weighs around 120 grams; the same cup dipped straight into the bag can hold 140 grams. Both figures are defensible, so two sites can disagree by 15% and neither is lying. We publish separate figures for each technique rather than picking one.
Are these conversions exact?
No, and no weight-to-volume conversion can be. Density shifts with packing, humidity, grind and brand. Treat every result here as a close approximation. If precision matters, weigh your ingredients.
Should I use grams or cups?
Grams, whenever you have a scale. Weight does not change with how you fill the cup, so it is reproducible, and weighing straight into the bowl means less washing up. Cups are convenient, not accurate.
Which cup size do you use?
The US cup, 236.6 millilitres. A metric cup is 250 ml and an imperial cup is about 284 ml, so if you are following a British or Australian recipe our figures will run slightly small.
Common amounts
Each of these works one weight of rolled oats through in full.