½ Cup of Oats in Grams
45 g in a US cup — and what that figure assumes
½ cup of rolled oats weighs 45 grams, measured in a US cup.
That figure comes from one number: a full US cup of rolled oats is 90 g. Everything else on this page is that number scaled.
Rolled oats are light and airy. Spoon them into the cup and level it — pressing them down can add 15 g or more to a cup.
Whose cup you mean changes the answer. A 250 ml metric cup — the standard in the UK, Australia, New Zealand and Canada — is 5.7% larger than the 236.6 ml US cup, so half a cup of rolled oats is 47.6 g there rather than 45 g.
½ cup of oats in each cup standard
| Cup standard | Size | Grams | Ounces |
|---|---|---|---|
| US customary | 236.6 ml | 45 g | 1.59 oz |
| Metric (UK, AU, NZ, CA) | 250 ml | 47.6 g | 1.68 oz |
| Imperial (older UK) | 284 ml | 54 g | 1.91 oz |
A recipe that just says "cups" is almost always American. If yours came from a British, Australian or New Zealand source, take the metric row — on a 45 g measure the gap is 2.6 g.
Halving and doubling oats
Recipes get scaled more often than they get followed exactly. These are the portions of rolled oats a cook actually reaches for, already weighed out.
| Cups | Grams | Ounces | Tablespoons |
|---|---|---|---|
| ¼ cup | 22.5 g | 0.79 oz | 4 |
| ⅓ cup | 30 g | 1.06 oz | 5.33 |
| ½ cup | 45 g | 1.59 oz | 8 |
| ⅔ cup | 60 g | 2.12 oz | 10.67 |
| ¾ cup | 67.5 g | 2.38 oz | 12 |
| 1 cup | 90 g | 3.17 oz | 16 |
| 1½ cups | 135 g | 4.76 oz | 24 |
| 2 cups | 180 g | 6.35 oz | 32 |
| 3 cups | 270 g | 9.52 oz | 48 |
½ cup of oats in other units
| Unit | Amount |
|---|---|
| Grams | 45 g |
| Ounces (weight) | 1.59 oz |
| Pounds | 0.099 lb |
| Tablespoons | 8 |
| Teaspoons | 24 |
| Millilitres (the space it fills) | 118 ml |
These are old-fashioned rolled oats at 90 g per cup. Quick oats are cut smaller and settle to 85 g, and steel-cut oats are much denser at 160 g.
½ cup of something else
The same cup holds a different weight of everything, because ingredients do not weigh the same for their size.
| Ingredient | Grams per US cup | ½ cup weighs |
|---|---|---|
| Flour | 125 g | 62.5 g |
| Butter | 227 g | 114 g |
Frequently asked questions
How many grams is ½ cup of oats?
½ cup of rolled oats is 45 grams in a US cup, based on 90 g per full cup. In a 250 ml metric cup it is 47.6 g.
Is that weighed or measured?
Measured, then weighed on a scale. Rolled oats are light and airy. Spoon them into the cup and level it — pressing them down can add 15 g or more to a cup. A scale skips the question, which is why recipes that care about the result give grams.
How many tablespoons is ½ cup of oats?
8 tablespoons, or 24 teaspoons — 5.63 g per tablespoon for rolled oats.
How many ounces is ½ cup of oats?
1.59 ounces by weight. That is not the same as fluid ounces — ½ cup is 4 US fluid ounces of space, whatever is filling it.
Why do different sites give different grams for ½ cup of oats?
Because a cup is a volume and the weight depends on how it was filled, and on whose cup. This site uses 90 g per US cup. These are old-fashioned rolled oats at 90 g per cup. Quick oats are cut smaller and settle to 85 g, and steel-cut oats are much denser at 160 g.