Grains and starches

Oatmeal nutrition, by serving and by method.

1 cup of cooked oatmeal lands at 166 calories and brings 5.9 g of protein with it. That is USDA’s figure for “Cereals, oats, regular and quick, unenriched, cooked with water (includes boiling and microwaving), without salt”. Cook it differently and that moves: the spread across the forms below is 71 to 379 calories per 100 g. Choose how much you are eating and the panel does the arithmetic from there.

By Alen Yaco · Updated 20 September 2026

Drawn from USDA FoodData Central, FDC 173904, 173905. No account, no upload, percentages against FDA Daily Values.

Calories in oatmeal, serving by serving

1 cup of cooked oatmeal supplies 166 calories, which scales to 71 per 100 g. Each serving listed underneath was weighed by USDA rather than estimated.

What oatmeal offers in protein

1 cup of cooked oatmeal carries 5.9 g of protein, which is 12 percent of the 50 g Daily Value. Only 14 percent of its calories come from protein, so treat oatmeal as something you eat for other reasons and count the protein as a bonus.

Of every 100 calories, 14 come from protein, 19 from fat and 67 from carbohydrate.

What cooking does to oatmeal

As sold oatmeal comes in at 379 calories per 100 g against 71 for cooked, a gap of 434 percent. What explains it is water absorbed during cooking, which dilutes every gram.

Every row below is the same 234 g of oatmeal, so the only thing that differs is the method.

Buying, cooking and using oatmeal

Oatmeal consists of groats that are husked, then steamed and flattened, or cut into smaller pieces. Look for whole steel-cut groats, rolled flakes, or quick-cooking varieties. Avoid packages with powdery residue at the bottom, which indicates excessive friction during handling and leads to a gummy texture. Seek uniform size for even water absorption.

Starch in the groats gelatinises when heated in liquid, releasing amylose which thickens the pot. Stirring too vigorously during this process ruptures the starch cells, making the porridge gluey. The common error is boiling the oats too rapidly without stirring occasionally, which scorches the bottom layer. Gentle simmering yields a creamy consistency.

This grain serves as a base for sweet porridge with milk and fruit, or savoury dishes with stock and salt. In Scottish cooking, it coats herrings before frying. In Northern European soups, it acts as a thickening agent. It pairs well with toasted nuts, fresh berries, or sharp cheese.

Vitamins and minerals in oatmeal

What 1 cup of cooked oatmeal supplies most of: 23 percent of a day’s selenium, 21 percent of a day’s zinc, 15 percent of a day’s thiamin. All rows below respond to the serving you chose.

How far oatmeal goes in a day

1 cup of cooked oatmeal: 8 percent of 2,000 calories, 12 percent of the protein Daily Value. Those are reference numbers; the TDEE calculator finds yours, and the macro calculator converts them to grams.

Cooking with oatmeal: three recipes

From the Calorie Counter Team: three dishes built around oatmeal, with per-serving nutrition calculated from the USDA data for every ingredient that goes in.

Breakfast · British

Classic Milk Porridge

A traditional breakfast porridge made with rolled oats and whole milk.

15 min · serves 2

280kcal

11gprotein

8.1gfat

41gcarbs

Ingredients

• rolled oats 100 g
• whole milk 300 g
• water 200 g
• salt 2 g

Method

1. Combine the rolled oats, whole milk, water, and salt in a saucepan.
2. Bring the liquid to a boil over medium-high heat.
3. Reduce the heat to low and simmer for 10 minutes.
4. Stir the mixture frequently to prevent sticking.
5. Divide the porridge into two bowls.

Nutrition per serving, calculated across 4 USDA ingredient records. Expect small differences once cooked.

Side · Scottish

Pan-Fried Oat Flatbreads

Simple flatbreads made from ground oats and water cooked in a frying pan.

20 min · serves 2

347kcal

11gprotein

12gfat

49gcarbs

Ingredients

• oat flour 150 g
• boiling water 120 g
• olive oil 10 g
• salt 2 g

Method

1. Mix the oat flour and salt together in a bowl.
2. Pour the boiling water into the flour mixture.
3. Stir the mixture until a firm dough forms.
4. Divide the dough and roll into two flat rounds.
5. Heat the olive oil in a frying pan.
6. Fry each flatbread for three minutes on each side.

Nutrition per serving, calculated across 4 USDA ingredient records. Expect small differences once cooked.

Breakfast · British

Classic Stove-top Porridge

A traditional warm breakfast porridge cooked on the hob.

10 min · serves 2

302kcal

12gprotein

8.1gfat

47gcarbs

Ingredients

• Rolled oats 100 g
• Whole milk 300 g
• Water 200 g
• Fine salt 2 g
• Honey 15 g

Method

1. Combine the rolled oats, whole milk, water, and salt in a medium saucepan.
2. Place the saucepan over medium heat and bring the mixture to a simmer.
3. Cook for five minutes, stirring constantly with a wooden spoon until the mixture thickens.
4. Remove the saucepan from the heat source.
5. Stir in the honey and divide the porridge into two bowls.

Nutrition per serving, calculated across 5 USDA ingredient records. Expect small differences once cooked.

Calorie Counter Team, food critic

What a meal with oatmeal adds up to

A worked example, every line from the same USDA data as the table above. Swap any of it; the arithmetic is the point, not the menu.

Grains and starches: where oatmeal sits

Per 100 g, each in the form its own page leads with; the second column says which.

Oatmeal, asked and answered

How many calories does 1 cup of cooked oatmeal have?

166 calories, according to USDA FoodData Central: the record is “Cereals, oats, regular and quick, unenriched, cooked with water (includes boiling and microwaving), without salt”, FDC 173905. That works out at 71 per 100 g.

How much protein is in oatmeal?

2.5 g per 100 g, so 1 cup of cooked oatmeal supplies 5.9 g. Against the Daily Value that is 12 percent.

Does cooking change the calories in oatmeal?

Yes, by a measurable amount: 234 g goes from 166 calories (cooked) to 887 (as sold), depending on preparation.

Does oatmeal fit a calorie deficit?

Weight change comes from the whole week’s intake. 1 cup of cooked oatmeal contributes 166 calories and 5.9 g of protein (14 percent of its energy), which means it needs a protein-rich partner on the plate.

Why does oatmeal turn out sticky instead of creamy?

Too much agitation during cooking releases excess starch. To prevent stickiness, stir the oats gently and only occasionally. Rinsing steel-cut varieties before cooking also removes loose starch from the surface.

Can steel-cut oats be used instead of rolled oats in baking?

Not without prior preparation. Steel-cut oats remain hard and gritty when baked dry. You must soak them in boiling liquid until soft before adding them to batters, or the texture of the bake will be ruined.

Sources

• Cereals, oats, regular and quick, not fortified, dry — USDA FoodData Central, FDC ID 173904
• Cereals, oats, regular and quick, unenriched, cooked with water (includes boiling and microwaving), without salt — USDA FoodData Central, FDC ID 173905
• Daily Values for nutrition labelling, 21 CFR 101.9