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Crab nutrition in one line: crab is a lean shellfish that is low in calories and fat and rich in vitamin B12, zinc, copper and selenium, with sodium that varies a lot by species and processing. In USDA data, 3 ounces of cooked blue crab have 71 calories and 15.2 grams of protein, and 3 ounces of Alaska king crab carry more than four times the Daily Value for vitamin B12. So, is crab healthy? For most people it is a nutrient-dense seafood, with two caveats: sodium, and the fact that crab is a major food allergen. This guide covers crab calories by type, how imitation crab compares, and the FDA safety facts worth knowing.
Peptide Labs does not sell crab or seafood products. This article is general nutrition information, not medical advice.
Key Takeaways
- Crab calories are low: about 71 to 98 per 3 ounces cooked, depending on the species, in USDA data.
- Real crab is a strong source of vitamin B12, zinc, copper and selenium.
- Sodium ranges widely, from about 14% of the Daily Value per 3 ounces of Dungeness crab to about 40% for Alaska king crab.
- Imitation crab is made from surimi, a fish paste; it has less than half the protein of blue crab and more carbohydrate.
- Crab is a crustacean shellfish, one of the nine major food allergens under US law, and it sits in the FDA/EPA lowest-mercury group.
Crab nutrition and crab calories by type
The table uses the USDA FoodData Central SR Legacy database with FDC IDs. Values are per 3 ounce (85 gram) cooked portion, with the percent of the FDA Daily Value in brackets.
| Per 3 oz cooked (USDA FDC ID) | Calories | Protein (% DV) | Sodium (% DV) | Vitamin B12 (% DV) | Zinc (% DV) | Copper (% DV) |
|---|---|---|---|---|---|---|
| Blue crab (174205) | 71 | 15.2 g (30%) | 336 mg (15%) | 2.83 mcg (118%) | 3.2 mg (29%) | 0.69 mg (77%) |
| Blue crab, canned (171966) | 71 | 15.2 g (30%) | 479 mg (21%) | 2.83 mcg (118%) | 3.2 mg (29%) | 0.69 mg (77%) |
| Dungeness crab (172007) | 94 | 19.0 g (38%) | 321 mg (14%) | 8.82 mcg (368%) | 4.65 mg (42%) | 0.62 mg (69%) |
| Queen crab (172008) | 98 | 20.2 g (40%) | 587 mg (26%) | 8.82 mcg (368%) | 3.05 mg (28%) | 0.53 mg (59%) |
| Alaska king crab (174202) | 82 | 16.5 g (33%) | 911 mg (40%) | 9.78 mcg (408%) | 6.48 mg (59%) | 1.0 mg (111%) |
| Imitation crab, made from surimi (174203) | 81 | 6.5 g (13%) | 450 mg (20%) | 0.48 mcg (20%) | 0.28 mg (3%) | 0.03 mg (3%) |
Real crab also brings selenium: USDA lists 34 to 40.5 micrograms per 3 ounces across these species, roughly 62% to 74% of the Daily Value. Fat is around 1 gram per serving and carbohydrate is close to zero. Cholesterol ranges from 45 milligrams per 3 ounces for king crab to 82 milligrams for blue crab in USDA data (15% to 27% DV); our cholesterol food guide explains how dietary cholesterol is discussed today. For B12 and zinc across many foods, see our guides to vitamin B12 in foods and zinc in foods, and our copper guide for that mineral.
Crab calories in common portions
- One Alaska king crab leg (134 grams of meat): about 130 calories and 25.9 grams of protein, with 1,436 milligrams of sodium (62% DV) in USDA data.
- One whole cooked Dungeness crab (127 grams of meat): about 140 calories and 28.3 grams of protein.
- One cup of flaked blue crab (118 grams): about 98 calories and 21.1 grams of protein.
- One home-recipe crab cake (60 grams): about 93 calories, 12.1 grams of protein and 4.5 grams of fat; restaurant versions vary with the binder and frying.
Melted butter and dipping sauces can add more calories than the crab itself, so it helps to count them separately. For protein comparisons across many foods, see our protein food list.
Imitation crab vs real crab
Imitation crab, sometimes sold as crab sticks or krab, is made from surimi. USDA’s database lists it as “made from surimi” and files surimi itself under fish, so imitation crab is a fish product, not crab. The USDA numbers show how different it is.
| Per 3 oz (USDA FDC ID) | Calories | Protein (% DV) | Carbs | Sugars | Sodium (% DV) |
|---|---|---|---|---|---|
| Blue crab, cooked (174205) | 71 | 15.2 g (30%) | 0 g | 0 g | 336 mg (15%) |
| Imitation crab (174203) | 81 | 6.5 g (13%) | 12.8 g | 5.3 g | 450 mg (20%) |
| Surimi, plain fish paste (173702) | 84 | 12.9 g (26%) | 5.8 g | 0 g | 122 mg (5%) |
Compared with real blue crab, imitation crab has less than half the protein, about 13 grams of carbohydrate including some sugar, and much less vitamin B12 and zinc. It also has more carbohydrate and sodium than plain surimi in USDA data, a sign that other ingredients are added during processing. Recipes differ by brand, so the ingredient list is the only reliable guide.
For allergies, read the label closely. Because imitation crab is made from fish, it contains a major allergen even though it contains little or no crab. FDA labeling rules require the specific species of fish and of crustacean shellfish to be named in the ingredient list or Contains statement, so check both before eating it if you have any food allergy.
Is crab healthy? Benefits and watch-outs
- Lean protein: real crab is mostly protein and water, with very little fat. The Dietary Guidelines for Americans 2020-2025 count seafood, including shellfish, as a protein foods subgroup.
- Micronutrients: high in vitamin B12, copper and selenium, and a good source of zinc in USDA data.
- Sodium: king crab and queen crab are high in sodium per serving before any seasoning; canned blue crab has more than fresh cooked. Our sodium guide covers label reading.
- Omega-3 fats: crab provides some, about 0.15 grams of EPA plus DHA per 3 ounces of blue crab, far less than oily fish; see our omega-3 guide.
- Purines: if you have been told to limit purines, our purine guide explains where shellfish fit.
Our sibling guide to scallops covers a mollusk with a different allergy status, and our guides to oysters and mussels cover other shellfish.
Crab allergy, mercury and FDA safety facts
Crab is a crustacean shellfish. Under section 201(qq) of the Federal Food, Drug, and Cosmetic Act, crustacean shellfish such as crab, lobster and shrimp are major food allergens, and FDA guidance says the specific species must be declared on labels. Anyone with a known shellfish allergy should avoid crab and ask an allergist about related foods.
On mercury, FDA and EPA advice about eating fish (revised October 2021) places crab in the lowest-mercury group of its chart. That advice targets people who are or might become pregnant, those who are breastfeeding, and young children.
Natural toxins are a harvest-area issue. FDA seafood guidance reports that domoic acid levels in Dungeness crab on the US west coast have exceeded guidance levels and required harvest closures, and that the viscera (the soft insides, sometimes called crab butter) of crabs and lobsters may pose a health hazard if harvested from contaminated waters. These toxins are not reliably destroyed by cooking. Commercial fisheries are managed around closures; recreational crabbers should check state advisories before crabbing.
For everyday handling, FoodSafety.gov says to cook crab until the flesh is pearly or white and opaque, and FDA advises cooking most seafood to 145 degrees F. CDC advises against eating raw or undercooked seafood because of Vibrio, and FDA lists pregnant women, young children, older adults and people with weakened immune systems as groups who should avoid raw or undercooked shellfish.
Frequently Asked Questions
How many calories are in crab?
About 71 calories in 3 ounces of cooked blue crab, 82 for Alaska king crab, 94 for Dungeness and 98 for queen crab, in USDA data.
How much protein is in crab?
Roughly 15 to 20 grams per 3 ounces cooked, depending on the species; one king crab leg has about 26 grams.
Is imitation crab real crab?
No. Imitation crab is made from surimi, a processed fish paste. It has less protein and more carbohydrate than real crab.
Is crab high in mercury?
No. FDA and EPA place crab in the lowest-mercury group of their fish advice.
Why is king crab so salty?
USDA lists 911 milligrams of sodium in 3 ounces of cooked Alaska king crab, about 40% of the Daily Value, before any seasoning.
Can I eat imitation crab with a shellfish allergy?
Read the label and ask an allergist. Imitation crab is a fish product, and fish is a major allergen; the label must name the species of fish and of any crustacean shellfish.
Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed October 2026.
Related guides: Scallops Nutrition: Protein, Sodium and Are Scallops Healthy?, Foods High in Zinc: USDA List for Meat Eaters, Vegetarians and Vegans, Shrimp Nutrition: Protein, Calories and Is Shrimp Healthy?, Types of Crab: NOAA Crab Species and 6 USDA Crab Entries.