One cup of rolled oats weighs 89 g, spooned and levelled, according to King Arthur Baking. Rolled oats — old-fashioned oats, steamed and flattened — are the lightest grain in this series by the cup, because the flattened flakes leave large air gaps between them. The cup weight of 89 g is the number you need for oatmeal, cookies, granola and crumble toppings, where oats are measured by the cup and the weight decides the texture. All weights on this page are approximate; the flake size varies by brand, so verify with a scale when precision matters.
Rolled Oats: weight and measurement table
The table below gives the weight of rolled oats in every measure you will use, from a teaspoon up to 2 cups, all derived from the King Arthur Baking figure of 89 g per cup, spooned and levelled. Every figure is approximate — spooned and levelled is a technique, not a machine setting — so when the recipe matters, weigh the ingredient on a kitchen scale instead.
| Amount | Weight (approx.) |
| --- | --- |
| 1 teaspoon | 1.9 g |
| 1 tablespoon | 5.6 g |
| 1/4 cup (4 tbsp) | 22.2 g |
| 1/3 cup | 29.7 g |
| 1/2 cup (8 tbsp) | 44.5 g |
| 3/4 cup (12 tbsp) | 66.8 g |
| 1 cup (16 tbsp) | 89 g |
| 2 cups | 178 g |
| 100 g | 1.1 cups |
There are 3 teaspoons in a tablespoon and 16 tablespoons in a cup, so you can move between any of these measures by multiplying or dividing. If a recipe calls for 100 g and you only have measuring cups, that is about 1.1 cups. Keep the cups to grams converter open while you cook and you will never need to do the arithmetic in your head.
What is Rolled Oats?
Rolled oats are old-fashioned rolled oats, steamed and flattened. Whole oat groats are steamed to soften them, then rolled between rollers into flat flakes, which cook faster than the whole groat and have a soft, chewy texture. They are used for oatmeal, cookies, granola and crumble toppings, and they are prized for their soluble fibre — beta-glucan — which helps lower cholesterol and keeps you full. They cook in about 5 minutes, against 30 minutes for steel-cut oats, which is why they are the standard breakfast oat. They keep for up to 6 months in an airtight container in a cool, dry place, and they absorb moisture easily, so keep them sealed.
How to measure Rolled Oats correctly
Rolled Oats is measured spooned and levelled, and the method matters more than most cooks realise. For dry ingredients, spoon the ingredient into the measure with a smaller spoon, letting it fall loosely, then sweep a knife across the top to level it — never dip the measuring cup into the bag, because dipping compresses the ingredient and adds up to 20 percent. For liquids, pour into a liquid measuring jug and read the level at eye height, or weigh directly into the bowl, which is the most accurate method of all. The King Arthur Baking figure used on this page is 89 g per cup, and it is the figure the site's converters use, so the numbers here and the numbers in the tool always agree. Confidence in this figure is high.
Worked examples
A bowl of oatmeal for two
A bowl of oatmeal for two uses 1 cup of rolled oats — 89 g — simmered with 2 cups of water or milk. The weight matters because oatmeal is a ratio: 89 g of oats to 480 g of liquid gives a creamy porridge, while a cup too many makes it thick and stodgy. Weighing the oats also lets you scale the recipe — a single serving needs 1/2 cup (45 g), and a family batch for six needs 3 cups (267 g) — and the oats are cooked for 5 minutes, until they are tender and the liquid has thickened. The porridge is served with brown sugar, fruit and a splash of cream.
An oatmeal cookie batch
An oatmeal cookie recipe uses 2 cups of rolled oats — 178 g — with 1 cup of flour, butter and sugar. The weight is useful because the oats are the cookie's texture: 178 g of oats against 120 g of flour gives a cookie that is chewy and hearty, with visible flakes. Weighing the oats keeps the ratio exact — a cup too many and the cookies are dry and crumbly, a cup too little and they spread flat and lose their chew. The dough is chilled for 30 minutes before baking, which stops the cookies spreading, and they are baked for 12 minutes, until the edges are golden and the centres are still soft.
A granola for the week
A granola batch uses 4 cups of rolled oats — 356 g — tossed with nuts, seeds, honey and oil, then baked until crisp. The weight matters because granola is a ratio recipe: 356 g of oats to 100 g of honey and 60 g of oil gives clusters that hold together without being sticky. Weighing the oats lets you scale the batch — a half batch needs 178 g, and a double batch needs 712 g — and the granola is baked at a low temperature, stirred every 10 minutes, until it is golden and crisp. It keeps for 2 weeks in an airtight jar, and a serving is about 45 g, or half a cup.
Rolled, steel-cut and quick oats
Not all oats are the same, and the difference is processing. Steel-cut oats are whole oat groats cut into pieces — they are chewy, hearty and take 30 minutes to cook, and they weigh 140 g per cup, because the dense pieces pack tightly. Rolled oats are steamed and flattened — they cook in 5 minutes, have a soft, chewy texture, and weigh 89 g per cup, because the flat flakes leave air gaps. Quick oats are rolled oats cut into smaller pieces — they cook in 1 minute, have a softer, mushier texture, and weigh about the same as rolled oats per cup. The three are not interchangeable: steel-cut oats in a cookie recipe stay hard and raw, quick oats in a granola turn to dust, and rolled oats in a steel-cut porridge cook too fast and go mushy. The practical rule is to use the oat your recipe specifies, and to weigh it — 89 g per cup for rolled, 140 g for steel-cut — because the volume measure is meaningless across types. And for baking, rolled oats are the standard: they hold their shape, add chew, and give cookies and crumbles their characteristic texture.
What to use instead
There is no single perfect substitute for rolled oats in every recipe, because it does different jobs in different dishes. In baking, the closest match is usually an ingredient from the same family used in a similar way — but always check a recipe written for the substitute rather than swapping blindly, and expect the texture and flavour to change. When a recipe depends on rolled oats for structure — as a binder, a leavener or a main ingredient — there is no substitute that behaves the same way, and the honest answer is to buy the ingredient or choose a different recipe. For a full list of tested swaps with ratios, see the substitution finder and the flour substitute converter.
Storage
Airtight container, cool and dry, up to 6 months. That is the headline, but the details matter. Store rolled oats in an airtight container, away from heat, light and strong smells — dry ingredients absorb odours readily, and a bag of flour stored next to the spices will taste of them within a week. Label the container with the date you opened it, so you know how long it has been there, and check it before you bake: if it smells off, tastes bitter, or shows any sign of moisture or insects, discard it. Buying in smaller quantities and using it promptly is better than buying in bulk and storing it for a year, because every ingredient loses flavour with time, even the ones that never truly go bad.
Frequently asked questions
How many grams is 1 cup of rolled oats?
One cup of rolled oats weighs 89 g, spooned and levelled, according to King Arthur Baking. One tablespoon weighs 5.6 g. Steel-cut oats weigh more at 140 g per cup, because the dense pieces pack tightly.
How many cups of rolled oats are in 500 g?
There are about 5.6 cups in 500 g of rolled oats (500 divided by 89 is 5.6 cups). A standard 500 g bag holds just over 5.5 cups.
Can I use quick oats instead of rolled oats?
In most baking, yes — quick oats work where rolled oats are used, but they absorb liquid faster and give a softer, less chewy texture. In granola and crumble toppings, rolled oats are better, because quick oats turn to dust. For porridge, quick oats cook in 1 minute against 5 minutes for rolled.
Can I use steel-cut oats instead of rolled oats?
Not without adjusting the cooking time and liquid. Steel-cut oats take 30 minutes to cook and need more water. They stay hard in cookies and granola. Use them for porridge, where their chewy texture is the point, and soak them overnight to shorten the cooking time.
How long do rolled oats last?
Up to 6 months in an airtight container in a cool, dry place. Discard them if they smell musty or rancid. Oats absorb moisture easily, so keep them sealed and away from strong smells.
Related pages
If you cook with this ingredient regularly, these pages will help: the cups to grams converter for any amount, the ingredient density lookup for the full table of 120 ingredients, the Rolled Oats cups to grams page for cup conversions, the Rolled Oats grams to cups page for working backwards from grams, and the Rolled Oats tablespoons to grams page for spoon measures. You may also want White Rice, Cornmeal.