A typical 3 oz cooked serving of blue crab contains 15.2 grams of protein (17.9 g per 100 g), which makes it a very good source of protein. That covers roughly 30% of the 50 g reference Daily Value, so it can anchor a high-protein meal for the day.
About 86% of the calories in blue crab come from protein, which makes it extremely protein-dense - close to the practical ceiling for a whole food. Foods in this band are the ones that let you raise your protein intake without raising your calorie intake much at all.
Among the 121 seafood in the database, blue crab ranks 98th by protein per serving, and 246th out of all 796 foods on the site. Set against ocean perch, another seafood entry in the database, a serving carries about 0.5 g less protein (ocean perch has 15.7 g per 3 oz cooked).
It is a complete protein - it supplies all nine essential amino acids in adequate amounts, so it can carry a meal's protein on its own. The serving above is measured by weight at 85 g. The per-100 g figure lets you compare it directly against any other food here, whatever its serving.
Source: USDA FoodData Central #174205 - "Crustaceans, crab, blue, cooked, moist heat" (SR Legacy, published 4/1/2019). Values are the published reference figures for that record, not lab measurements for a specific brand or batch.
Quick answers
Blue crab protein FAQ
How much protein is in blue crab per 100 g?
Blue crab has 17.9 g of protein per 100 g. A typical 3 oz cooked serving (85 g) provides 15.2 g.
Is blue crab a complete protein?
Yes. Blue crab is a complete protein - it supplies all nine essential amino acids in adequate amounts, so it can carry a meal's protein on its own.
How much of the Daily Value does a serving of blue crab cover?
A 3 oz cooked serving of blue crab contains 15.2 g of protein, about 30% of the 50 g reference Daily Value.
Is blue crab a good source of protein?
Blue crab is a very good source of protein, and about 86% of its calories come from protein, which makes it extremely protein-dense. Set against ocean perch, another seafood entry in the database, a serving carries about 0.5 g less protein (ocean perch has 15.7 g per 3 oz cooked).