Oats Grams to Cups Converter & Chart (g to cups)

One US cup of rolled oats (old-fashioned oats) weighs 90 grams (3.17 oz), quick oats weigh 80 grams per cup, and steel-cut oats weigh 160 grams per cup. Because oats vary drastically in particle size and density—from whole groats cut with steel blades to steam-flattened flakes—converting grams to cups requires matching the specific cut of oat. Use our interactive calculator and complete measurement tables below for porridge, granola, cookies, and baking.

Oats Grams to Cups Calculator



Cup Equivalent:

0.56 US Cups (1/2 cup + 1 tbsp)

Oats Conversion Chart: Grams to Cups Across Cuts

The table below provides cup conversions for standard recipe weights across rolled, quick, and steel-cut varieties:

Weight (Grams)Rolled Oats (90g/cup)Quick Oats (80g/cup)Steel-Cut Oats (160g/cup)Practical Kitchen Measure (Rolled)
25 g0.28 cup0.31 cup0.16 cup1/4 cup + 1/2 tablespoon
40 g (Serving)0.44 cup0.50 cup (1/2 c)0.25 cup (1/4 c)Just under 1/2 cup (7 tbsp)
50 g0.56 cup0.63 cup0.31 cup1/2 cup + 1 tablespoon
60 g0.67 cup (2/3 cup)0.75 cup (3/4 cup)0.38 cupExactly 2/3 cup
75 g0.83 cup (5/6 cup)0.94 cup0.47 cup3/4 cup + 1 tablespoon
90 g1.00 cup1.13 cup0.56 cupExactly 1 full US cup
100 g1.11 cup1.25 cup (1 1/4 c)0.63 cup1 cup + 2 tablespoons
120 g1.33 cup (1 1/3 c)1.50 cup (1 1/2 c)0.75 cup (3/4 c)1 1/3 cups
150 g1.67 cup (1 2/3 c)1.88 cup0.94 cup1 2/3 cups (or 1 1/2 cups + 2.5 tbsp)
180 g2.00 cups2.25 cups1.13 cupsExactly 2 full US cups
200 g2.22 cups2.50 cups1.25 cups2 1/4 cups
250 g2.78 cups3.13 cups1.56 cups2 3/4 cups

Why Oat Weight Varies: Flake Density Explained

Because oats are sold in different processed forms, scoop volume changes significantly:

  • Rolled Oats (Old-Fashioned, 90g/cup): Oat groats that are steamed and rolled into flat flakes. They trap air between flakes, making them light and porous.
  • Quick / Instant Oats (80g/cup): Rolled thinner and cut into finer fragments. When scooped loosely, they measure about 80g per cup.
  • Steel-Cut / Irish Oats (160g/cup): Intact groats chopped into pinhead pieces without steaming or flattening. With virtually zero air pockets, steel-cut oats weigh nearly double the mass of rolled oats per cup.
  • Oat Flour (100g/cup): Finely ground whole oats. 1 cup of oat flour weighs 100g (spooned and leveled).

Frequently Asked Questions

How many cups is 50 grams of oats?

50 grams of rolled oats equals 0.56 US cups (roughly 1/2 cup plus 1 tablespoon). If using quick oats, 50 grams equals 0.63 cups (roughly 5/8 cup).

How many grams of rolled oats are in 1 cup?

One US cup of rolled oats weighs 90 grams (3.17 ounces). Two cups equal 180 grams.

How many cups is 40g of oatmeal?

A standard 40g breakfast serving of rolled oats equals about 0.44 cups (7 tablespoons, or slightly under 1/2 cup). For quick oats, 40 grams is exactly 1/2 cup.

How many grams is 1/2 cup of oats?

One-half cup (1/2 cup) of rolled oats weighs 45 grams. One-half cup of quick oats weighs 40 grams, and 1/2 cup of steel-cut oats weighs 80 grams.