Crab is one of the leanest and most protein-dense types of seafood, but the calorie count depends heavily on the species, how it is prepared, and whether you add butter or sauce. A cup of cooked crab meat is a convenient reference for meal planning, yet portions vary: lump meat packs differently than flaked meat, and canned crab can carry extra sodium. This calculator removes the guesswork by converting your portion to grams and applying species-specific nutrition data drawn from USDA reference values.
Choose from blue crab, Dungeness crab, Alaskan King crab, canned blue crab, or imitation crab, then enter the amount in cups, ounces, or grams. The calculator returns total calories, protein, fat, and carbohydrates, plus a short step-by-step breakdown that shows exactly how each value was estimated. Optional add-ons for melted butter and cocktail sauce let you see how common sides change the final count.
Use this tool for portion-aware meal prep, macro tracking, or simply to make an informed choice at a seafood restaurant or crab boil. It is designed for anyone counting calories without spending time searching nutrition tables.
🦀 Crab Calories Per Cup Calculator
Estimate the calories, protein, fat, and carbs in a cup of crab meat — by type, and with or without common add-ons like butter or cocktail sauce.
Estimates are based on USDA reference data; actual values vary by brand, cooking method, and moisture content.
How This Crab Calorie Calculator Works
The tool starts by converting your chosen portion into grams of cooked crab meat. US nutrition labels and USDA reference data express crab macros per 100 grams, so converting to grams makes the arithmetic transparent. A standard US cup of flaked cooked crab meat weighs about 135 grams, though the exact weight can drift by 10–20 grams depending on whether the meat is packed loosely, firmly packed, or includes shell fragments.
Once the portion is expressed in grams, the calculator multiplies the per-100-gram energy and macronutrient values by that weight. For example, blue crab at 103 kcal per 100 g gives 139 kcal for a 135 g cup. The same calculation is applied to protein, fat, and carbohydrates. Optional add-ons are then added as straightforward increments: 1 tbsp of salted butter contributes about 102 kcal and 11.5 g of fat, while 2 tbsp of cocktail sauce adds about 30 kcal and 6 g of carbohydrates.
Nutritional Values by Crab Type
The table below summarizes the per-100-gram values used in the calculator. These are cooked-meat values unless noted; imitation crab here represents surimi-based products, which contain added starch and therefore contain carbohydrates.
| Crab type | Calories | Protein | Fat | Carbs |
|---|---|---|---|---|
| Blue crab (cooked) | 103 kcal | 21.9 g | 1.6 g | 0 g |
| Dungeness crab (cooked) | 110 kcal | 22.3 g | 1.2 g | 0 g |
| Alaskan King crab (cooked) | 97 kcal | 19.4 g | 1.5 g | 0 g |
| Canned blue crab | 89 kcal | 19.1 g | 1.0 g | 0 g |
| Imitation crab (surimi) | 95 kcal | 10.0 g | 0.9 g | 12.0 g |
Because all of these products are naturally very low in carbohydrates, the carb column matters most when comparing real crab to imitation crab. Imitation crab is often starch-bound and may contain added sugar, so it behaves quite differently in a low-carb eating plan.
Worked Examples
Example 1: 1 cup of blue crab. Blue crab contributes about 103 kcal per 100 g. Multiply by 135 g and divide by 100 to get 139 kcal. Protein works out to about 29.6 g, fat to 2.2 g, and carbs to 0 g.
Example 2: 6 oz of Alaskan King crab with butter. Six ounces equals about 170 g. King crab at 97 kcal per 100 g gives 165 kcal from the meat alone. Adding 1 tbsp of melted butter raises the total to roughly 267 kcal and 19.6 g of fat.
These examples show why portion size and add-ons move the total so much: plain crab is a high-protein, low-fat choice, but a butter-dipped crab boil can become a high-fat meal.
Tips for Accurate Portion Sizing
- Weigh the cooked meat after removing shells, not the whole crab. Shells and cartilage can make up a large share of the raw weight and skew your estimate.
- Use a kitchen scale when precision matters. A “cup” can be packed loosely or firmly, changing the actual grams by 15–20%.
- If you eat crab legs, remember that the edible yield from a leg is much lower than the total leg weight. Weigh only the meat you actually eat.
- For canned crab, drain it well. Packing liquid adds weight but almost no calories, so using the drained weight gives the most accurate result.
- Watch sodium, not just calories. Canned and imitation crab can be high in sodium even when calories are low.
Limitations & Accuracy Notes
The values in this calculator are averages from laboratory analyses and should be treated as estimates, not exact amounts. Real crab can vary with season, diet, cooking method, and moisture content. Steamed or boiled crab may retain more water than roasted or fried crab, and any added flour, breading, or seasoning is not included unless you check the add-on boxes or account for it separately.
There is also genuine variation between sources. A given crab species might appear as 95 kcal per 100 g in one database and 110 kcal per 100 g in another depending on the specific sample and preparation. For medical or weight-loss decisions, prefer a consistent database such as USDA FoodData Central and track your portions the same way each time.
Frequently Asked Questions
How many calories are in one cup of crab meat?
For plain cooked blue crab, a 135 g cup typically contains about 135–145 calories. Dungeness crab runs a little higher at around 140–150 calories per cup, while Alaskan King crab is closer to 125–135 calories. Canned crab is often the lowest at roughly 115–125 calories per cup.
Should I weigh crab meat raw or cooked?
Weigh it cooked and drained. Nutrition labels for seafood are generally based on cooked edible meat unless the package says otherwise. Cooking removes water, so the same 100 g portion of raw meat will not weigh 100 g after cooking.
Is imitation crab a healthy swap for real crab?
It is lower in protein and contains added carbs, but it is also usually cheaper and convenient. Imitation crab is not a nutritionally equivalent substitute, especially for someone aiming for high protein or very low carbs. It also tends to be higher in sodium than fresh-cooked crab.
If you eat other shellfish and want a quick comparison, the Lobster Nutrition Calculator offers the same type of per-serving breakdown for lobster meat.