Cereal vs Oatmeal vs Granola: Nutrition Comparison

Three breakfast options dominate the grain aisle, and each carries a reputation. Oatmeal is the virtuous choice, granola is the health food that might not be, and cereal is the convenient one everyone assumes is unhealthy. The real picture is more nuanced: the gaps within each category are often bigger than the gaps between them. This comparison uses USDA FoodData Central reference values and current product labels, checked in October 2026, so every number can be traced to a source.

Head-to-Head: Typical Servings

Comparing real products at their labeled serving sizes shows how much depends on which box or bag you choose.

Per labeled serving	Original Cheerios	Honey Nut Cheerios	Quaker Old Fashioned Oats (dry)	Cascadian Farm Oats & Honey Granola	Cascadian Farm No Added Sugar Blueberry Vanilla Granola
Serving	1 1/2 cups (39g)	1 cup (37g)	1/2 cup (40g)	2/3 cup	1/2 cup (52g)
Calories	140	140	150	270	250
Added sugars	1g	12g	not listed (1g total)	14g	0g (7g total)
Fiber	4g	3g	4g	3g	4g
Protein	5g	3g	5g	6g	5g

Plain oats and plain O’s look remarkably similar per serving: about 140 to 150 calories, 4 g of fiber, 5 g of protein and very little sugar. The sweetened cereal and the conventional granola are where added sugar climbs, and granola servings carry far more calories because granola is dense.

Per 100 Grams: Energy Density

Weight-for-weight comparisons strip out serving-size differences. USDA FoodData Central lists plain dry rolled oats (regular and quick) at 379 calories, 13.2 g of protein, 10.1 g of fiber, 1 g of sugar and 6.5 g of fat per 100 g. Many ready-to-eat cereals land in a similar calorie range: working from their labels, Original Cheerios comes to about 360 calories per 100 g, Grape-Nuts about 345 and Kix about 400.

Granola is denser. The commercial granolas checked in FoodData Central run roughly 430 to 520 calories per 100 g, and USDA’s reference entry for homemade granola lists 489 calories, 24.3 g of fat and 19.8 g of sugar per 100 g. Nuts, seeds and oil add fat and calories, which is why a small-looking pour of granola can match a large bowl of cereal.

Fiber Comparison

A ½-cup (40 g) dry serving of Quaker Old Fashioned Oats lists 4 g of fiber. Part of the fiber in oats is beta-glucan, a soluble fiber that underpins one of the FDA’s authorized health claims: 3 g or more a day of beta-glucan soluble fiber from whole oats or barley, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. Foods must provide at least 0.75 g of that soluble fiber per reference amount to carry the claim, which is why a version of the statement appears on oat cereals such as Cheerios.

Some cereals beat oatmeal on fiber per serving. Kashi GO Original lists 13 g per 1¼ cups (58 g), Post Shredded Wheat 8 g per 1⅓ cups and Grape-Nuts 7 g per ½ cup. Others offer very little: Trix lists 1 g and Lucky Charms 2 g per serving. Granola varies from about 3 to 4 g in the Cascadian Farm examples above. For specific high-fiber picks, see our best healthy cereals guide.

Sugar Comparison

Oatmeal (plain): Quaker’s label lists 1 g of sugar per ½-cup dry serving, and USDA lists about 1 g per 100 g. Whatever you add on top determines the final total: a tablespoon of honey adds about 17 g.

Cereal: Ranges from 0 g (Post Shredded Wheat, Catalina Crunch) to 12 g of added sugars in Honey Nut Cheerios, Lucky Charms and Trix, and 15 g in a 1-cup serving of Cheerios Oat Crunch Oats ‘N Honey. The healthy-or-not question for cereal hinges on which box you pick. See our sugar content rankings for more brands.

Granola: Conventional granolas are often sweet; Cascadian Farm’s Oats & Honey lists 14 g of added sugars per ⅔ cup. But “granola is always sugary” is no longer true: Cascadian Farm’s no-added-sugar line lists 0 g of added sugars, with 4 to 7 g of total sugars per serving depending on the flavor and serving size.

For context, the Dietary Guidelines for Americans, 2025–2030, recommend no more than 10 g of added sugars in a single meal.

Protein Comparison

Plain oats list 5 g of protein per ½-cup dry serving, and USDA lists 13.2 g per 100 g. Mainstream cereals typically list 3 to 5 g per serving, while protein-focused cereals go much higher, from 8 g in Three Wishes and 11 g in Catalina Crunch to 22 g per cup in Wheaties Protein. The granolas above list 5 to 6 g.

None of the three is a high-protein breakfast on its own at standard servings. A cup of milk adds about 8 to 10 g of protein depending on the brand, and the Dietary Guidelines advise prioritizing protein foods such as dairy, eggs, nuts or seeds at every meal.

Convenience and Preparation

Cold cereal and granola need no cooking: pour, add milk or yogurt, and eat. Rolled oats need a few minutes on the stove or in the microwave, while quick and instant oats are faster. Overnight oats, soaked in milk or yogurt in the refrigerator, remove the morning cooking step but require planning the night before. For pure speed on a weekday morning, cold cereal and granola win, and both travel well as a dry snack.

Satiety: Which Keeps You Full Longest

The best-known study is a 1995 “satiety index” by Holt and colleagues in the European Journal of Clinical Nutrition, which fed groups of 11 to 13 people 240-calorie portions of 38 foods and compared how full they felt over two hours, with white bread set at 100%. Porridge (oatmeal) scored 209%, the highest of the seven breakfast cereals in the study, compared with 118% for cornflakes and 100% for muesli. Across all foods, higher protein, fiber and water content and a heavier serving weight were linked with greater fullness, while fat was linked with less.

Two caveats: the study used Australian products from the 1990s and small groups, and porridge cooked with water is heavy and watery for its calories, which may help explain its score given the study’s link between water content and fullness. The broader lesson still applies to any bowl: more fiber, more protein and more volume per calorie tend to be more filling.

Cost Comparison

Prices vary too much by store and promotion for a universal ranking, so compare unit prices (cost per ounce) where you shop. For reference, family-size boxes of name-brand cereals such as Cheerios and Quaker Life were listed at about $0.24 to $0.29 per ounce at Target in October 2026, and a smaller 8.9-oz box of Cheerios at about $0.37 per ounce. Specialty protein cereals cost far more: Magic Spoon listed a 7-oz box at $9.75 on its own site (about $1.39 per ounce), and Catalina Crunch a 9-oz bag at $8.99 (about $1.00 per ounce). To compare with oatmeal or granola, divide the shelf price by the ounces in the package and multiply by the weight of a serving you actually eat. For more on brand tiers, see our store brand vs name brand price guide.

When to Choose Each

Choose oatmeal when: You have a few minutes (or planned overnight oats), you want a filling bowl with no added sugar, or you are aiming for oat beta-glucan as part of a heart-healthy diet. Keep toppings in check, since sweeteners erase oatmeal’s sugar advantage quickly.

Choose cereal when: Speed matters, you are feeding kids who reject oatmeal, or you have picked a cereal with strong label numbers: low added sugar, a whole grain first and at least 3 g of fiber. Plain O’s and shredded wheat come close to oatmeal on paper.

Choose granola when: You want crunch as a topping on yogurt or fruit, in measured amounts. If granola is your main bowl, pick a lower-sugar version and check the calories per serving.

Key Takeaways

Plain oats and plain whole-grain cereals such as Original Cheerios are closer on nutrition than their reputations suggest: about 140 to 150 calories, 4 g of fiber and 5 g of protein per serving.
Within each category, the product choice matters more than the category: added sugars range from 0 g to 15 g in cereals and from 0 g to 14 g in the granolas checked.
Granola is the most energy-dense option, at roughly 430 to 520 calories per 100 g.
Oatmeal scored as the most filling breakfast cereal in the classic 1995 satiety index study; fiber, protein, water and volume all help.
All three benefit from added protein, such as milk, yogurt, eggs or nuts.

Next Steps

Find the best specific cereals in our Best Healthy Cereals 2026
Learn to decode the numbers in Reading Cereal Nutrition Labels
Build a complete morning meal with our Healthy Breakfast Checklist

Nutrition data from USDA FoodData Central and manufacturer labels, checked October 2026. Individual products vary; check the package you buy.

Sources

USDA FoodData Central: Cereals, oats, regular and quick, not fortified, dry (SR Legacy 173904); Cereals ready-to-eat, granola, homemade (SR Legacy 171646); branded entries for Quaker Old Fashioned Oats and Cascadian Farm granolas — accessed October 19, 2026
21 CFR 101.81, health claims: soluble fiber from certain foods and risk of coronary heart disease — eCFR — accessed October 19, 2026
Holt SH, Miller JC, Petocz P, Farmakalidis E. A satiety index of common foods. European Journal of Clinical Nutrition, 1995 — Macquarie University research record — accessed October 19, 2026
Satiety value (reproduces the 1995 satiety index results table) — Wikipedia — accessed October 19, 2026
Original Cheerios and Honey Nut Cheerios — Cheerios.com — accessed October 19, 2026
Oats & Honey Granola — Cascadian Farm — accessed October 19, 2026
Grape-Nuts and Shredded Wheat Original Spoon Size — Post Consumer Brands — accessed October 19, 2026
Dietary Guidelines for Americans, 2025–2030 (PDF) — USDA/HHS — accessed October 19, 2026
General Mills Family Size Cheerios, 18 oz and Quaker Life Original, 22.3 oz — Target — prices viewed October 19, 2026
Fruity Cereal — Magic Spoon and Dark Chocolate Protein Cereal — Catalina Crunch — accessed October 19, 2026