How many grams are in a cup of oats?

Oats cups to grams: quick conversion table

Here are the quantities you'll need for common American recipes.

These figures are rounded to the nearest gram and apply to ordinary dry old-fashioned or quick-cooking oats.

They aren't intended for cooked porridge, steel-cut oats, oat flour or instant porridge sachets.

Are American rolled oats the same as UK porridge oats?

Generally, yes. Most UK porridge oats are rolled oats, although the flakes can be different sizes.

American recipes often use names that aren't as familiar in British supermarkets.

Here's what we'd look for:

The important thing is the texture, rather than just the name on the packet.

Jumbo rolled oats have larger, thicker flakes that hold their shape well. Ordinary porridge oats may be rolled more finely and soften faster.

For a recipe that specifically wants old-fashioned rolled oats, I'd choose ordinary rolled oats or jumbo oats, especially if the texture is important.

Can I use porridge oats instead of rolled oats in American cookies?

Usually, yes, but the texture of your cookies may change.

American oatmeal cookies are often made with old-fashioned rolled oats. Their larger flakes give the biscuits a pleasantly chewy texture.

If you use finer porridge oats instead, the cookies may be softer and more uniform, with less noticeable oat pieces.

That doesn't necessarily make them worse. It's simply a different result.

For cookies where you want a chunky, chewy texture, jumbo or larger rolled oats are a good choice.

For softer cookies, ordinary finer porridge oats can work well.

If the recipe specifically calls for quick oats, follow that instruction where possible.

What about instant oats and steel-cut oats?

Neither should automatically replace ordinary rolled oats in a baking recipe.

Instant porridge oats are processed to cook very quickly. Some products also contain sugar, flavourings or milk powder.

They can behave differently in baking, and flavoured sachets could change the other ingredients in your recipe.

Steel-cut oats are different again. Instead of being flattened into flakes, the oat grains are cut into small pieces.

They're firmer and take considerably longer to soften.

For a recipe asking for ordinary rolled oats, don't use steel-cut oats unless the recipe specifically allows it.

Why do some conversion charts say 80g, 89g or 113g?

Because oats aren't all the same size or packed into a measuring cup in exactly the same way.

Different published references use different figures.

For example:

• Some Quaker US packaging gives 40g for half a cup, equivalent to about 80g for a full cup.
• King Arthur Baking lists 89g for one cup of ordinary old-fashioned or quick-cooking oats.
• King Arthur also lists 113g for one cup of its own rolled-oat product.

These figures reflect different products or measuring conventions. They're not three interchangeable answers for every bag of oats.

At Cupstograms, we've chosen 89g per US cup for our standard dry-oats conversion.

If the recipe you're following says 1 cup oats (80g), use its 80g measurement rather than substituting ours.

That's particularly useful in baking, where the balance of dry ingredients matters.

Should I measure oats before or after cooking?

Our conversion table is for dry oats, measured before cooking.

This distinction matters because oats absorb liquid when you make porridge.

A cup of cooked porridge contains water or milk, so it doesn't weigh the same as a cup of dry oats.

If an American cookie recipe asks for one cup of rolled oats, it normally means the dry oats straight from the packet, unless it specifically says otherwise.

Don't cook them first.

Similarly, if you're making overnight oats and the recipe asks for half a cup of oats, measure the dry oats before adding your milk or yoghurt.

Does the word oatmeal mean something different in America?

It can, which is another reason American recipes sometimes cause confusion.

In America, oatmeal commonly means porridge made from oats. You'll also see it used in names such as oatmeal cookies, where the recipe contains dry rolled oats.

In Britain, oatmeal can also mean oats that have been ground into a coarse meal rather than rolled into flakes.

So if an American baking recipe asks for rolled oats, don't automatically buy a packet of finely ground oatmeal.

Look at the actual ingredient description and use rolled oats unless the recipe says otherwise.

Is it better to weigh oats than measure them in cups?

Yes, particularly when you're following an unfamiliar American recipe.

If you have kitchen scales, weighing dry oats is quick and avoids having to find the correct size of US measuring cup.

For example, if your recipe asks for half a cup of ordinary oats and doesn't give a weight, you can weigh out about 45g using our reference.

If you do use a measuring cup, fill it without deliberately crushing or packing the flakes down, then level the top.

And remember that the recipe author's own gram measurement should always take priority over a general conversion table.

Where our figures come from

Cupstograms uses 89g per US cup of dry old-fashioned or quick-cooking oats. It's our consistent reference for the calculator and conversion tables.

Our research includes:

• King Arthur Baking's ingredient weight chart (opens in a new tab), which provides the 89g reference and separately identifies its heavier rolled-oat product.
• King Arthur's oatmeal cookie recipe (opens in a new tab), illustrating how recipes can specify their own gram measurements.
• Quaker Oats' guide to oat varieties (opens in a new tab) and baking substitutions (opens in a new tab), explaining the differences between rolled, quick, instant and steel-cut oats.
• HEART UK's guide to oats (opens in a new tab) and BBC Good Food's oat guide (opens in a new tab), covering the types commonly available in Britain.

For other amounts, use our Cups to Grams converter and select Oats.

The important thing to remember: for ordinary dry oats, Cupstograms uses 89g per US cup, or about 45g for half a cup. Choose the oat variety your recipe calls for, and follow its own gram measurements whenever they're provided.