Grams to Cups

Rolled oats Grams to Cups Converter

Convert rolled oats from grams to cups using ingredient-specific baking measurements.

100 grams of rolled oats ≈

1.12US cups

About 1 ⅛ cups

Based on 1 US cup of rolled oats = 89g

Data last verified: July 18, 2026

Convert grams to cups

Precision

100 grams of Rolled oats =

1.12US cups

Approximately 1 ⅛ cups

Based on 1 US cup of Rolled oats = 89g

Conversions are approximate and may vary by ingredient brand, packing, humidity, and measuring method.

1 US cup of Rolled oats = 89g

Measured lightly filled (as-packaged, not compacted, based on the US cup / 240 ml)

Rolled oats grams to cups conversion table

GramsCups
50g0.56 cups
100g1.12 cups
125g1.40 cups
150g1.69 cups
200g2.25 cups
250g2.81 cups
300g3.37 cups
500g5.62 cups

Kitchen fraction approximation

22g ≈ ¼ cup
30g ≈ ⅓ cup
45g ≈ ½ cup
59g ≈ ⅔ cup
67g ≈ ¾ cup

Sources & how they compare

SourceReported valueComparable source-cup valueTypeMeasurement methodAdopted hereChecked
King Arthur Baking — Ingredient Weight Chart89 g/1 source cup (exact volume unknown)89gDirectnot packed (old-fashioned or quick-cooking)Adopted2026-07-18
The Quaker Oats Company — Old Fashioned Oats (via nutritionvalue.org mirror)40 g/1/2 source cup (exact volume unknown)80gDerivedas packaged (manufacturer serving size)2026-07-18

A comparable source-cup value only scales a half-cup or tablespoon serving to one source cup. When a source does not state the cup's exact volume, we do not present it as a fixed-milliliter normalization.

Measurement notes

  • Rolled oats are bulky and full of air pockets, so scoop lightly rather than pressing them down.
  • Old-fashioned rolled oats and quick oats differ in size, which can shift the weight per cup by several grams.
  • Because oats settle during shipping and storage, gently shaking the container before measuring can change the result — measure loosely for consistency.

Common mistakes

  • Not measuring rolled oats the recommended way — lightly filled — is one of the most common sources of error.
  • Assuming 1 cup of rolled oats equals 240g like water — it is actually 89g per US cup.
  • Pressing the cup down instead of scooping it loosely.

Frequently asked questions

How many cups is 100 grams of rolled oats?

100 grams of rolled oats is about 1.12 cups, based on 1 US cup (240 ml) = 89g.

How many grams are in 1 cup of rolled oats?

1 US cup of rolled oats is about 89 grams, measured lightly filled.

Does 1 cup of rolled oats weigh the same in a metric cup?

No. A metric cup (250 ml) holds slightly more than a US cup (240 ml), so 1 metric cup of rolled oats is about 92.7g, compared with 89g in a US cup.

What's the best way to measure rolled oats accurately?

For the most accurate result, lightly filled, and use a kitchen scale when your recipe calls for a precise weight.

Can I convert cups of rolled oats back to grams?

Yes, use the Cups to Grams tool with rolled oats selected to convert any cup amount back into grams.

Why does rolled oats convert differently from other ingredients?

Grams measure weight and cups measure volume, so the conversion depends on how dense rolled oats is. A cup of rolled oats weighs 89g, while a denser or lighter ingredient weighs a different amount per cup.

Where do these numbers come from?

See how we measure ingredient density and verify each grams-per-cup value.