Rolled Oats — Cups to Grams Conversion
One cup of rolled oats weighs 90g, lighter than it looks since the flat flakes trap a large amount of air.
Rolled Oats Cups to Grams Chart
| Cups | Grams |
|---|---|
| ¼ cup | 23g |
| ⅓ cup | 30g |
| ½ cup | 45g |
| ¾ cup | 68g |
| 1 cup | 90g |
| 1½ cups | 135g |
| 2 cups | 180g |
| 3 cups | 270g |
Source: King Arthur Baking ingredient weight chart · Measurement method: Spooned & levelled
Tablespoon & Teaspoon Weights
| Measure | Grams | Notes |
|---|---|---|
| 1 tbsp (US/UK — 15ml) | 5.6g | Standard in US, UK, Canada |
| 1 tbsp (Australian — 20ml) | 7.5g | One-third larger than US/UK |
| 1 tsp (5ml — universal) | 1.9g | Same worldwide |
About Rolled Oats
Rolled oats are whole oat groats that have been steamed and rolled flat between rollers, giving them their familiar broad, flaky shape. Because the steaming pre-cooks the groat, rolled oats hydrate quickly in a batter without needing to be soaked first, and they hold their shape well during baking, adding a hearty chew to cookies, a moist, dense texture to flapjacks, and a wholesome bite to crumble toppings.
Why the Weight Per Cup Varies
Rolled oats are large, flat, and irregularly shaped, trapping a substantial amount of air between the flakes. A spooned cup weighs only 90g, far lighter than it looks and considerably lighter than wheat flour despite occupying a similar visual volume. Because the flakes resist compression better than fine flour, the gap between a spooned and a scooped cup is smaller here than with flour, though a light touch still gives the most reliable result.
Names in Different Countries
"Rolled oats" (US/Canada/AU) is often called "old-fashioned oats" in the US to distinguish it from quick oats. In the UK, the same product is usually labelled "porridge oats."
Common Recipe Uses
Flapjacks, ANZAC biscuits, oatmeal cookies, granola, crumble toppings, muesli, overnight oats.
Substitutions
Quick oats substitute 1:1 by weight, giving a softer, less chewy result. Steel-cut oats are too hard and dense to substitute without pre-cooking first.
Frequently Asked Questions
Yes — UK "porridge oats" and US/AU "rolled oats" are the same product, simply named differently by region.
Yes, 1:1 by weight — rolled oats give a chewier, more textured result than the softer texture quick oats produce.
Not usually — they are pre-cooked during rolling and hydrate quickly in most batters, though soaking for 20 to 30 minutes gives a noticeably softer result in overnight oats.
5.6g for a US/UK tablespoon (15ml), or 7.5g for an Australian tablespoon (20ml).
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