Every 100 kcal of crab brings 20 g of protein. On that measure it ranks 37th of the 121 seafood in this database and 55th of all 796 foods on the site. Measured by weight instead, its 19.4 g per 100 g ranks 88th in its group.
About 80% of the calories in 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.
Weight for weight, crab has 12.6 g of protein for each gram of fat (19.4 g against 1.54 g per 100 g).
Set against haddock, another seafood entry in the database, a serving carries about 0.5 g less protein (haddock has 17 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 quoted here is measured by weight at 85 g, and it covers about 33% of the 50 g FDA Daily Value for protein.
Serving sizes
Protein in common portions of crab
Protein and calories in Crab for 100 g, the site serving and USDA household portions.
Portion
Weight
Protein
Calories
100 g
100 g
19.4 g
97 kcal
3 oz cooked (serving used here)
85 g
16.5 g
82 kcal
1 leg
134 g
26 g
130 kcal
Portion weights are the household measures listed on the USDA record; protein and calories scale from the per-100 g figures.
Amino acids
Essential amino acids in crab
The nine essential amino acids in Crab, per 100 g, per serving and per gram of protein.
Amino acid
Per 100 g
Per serving
mg per g protein
leucine
1.54 g
1.31 g
79
lysine
1.68 g
1.43 g
87
valine
0.91 g
0.77 g
47
isoleucine
0.938 g
0.8 g
48
threonine
0.783 g
0.67 g
40
phenylalanine
0.817 g
0.69 g
42
methionine
0.545 g
0.46 g
28
histidine
0.393 g
0.33 g
20
tryptophan
0.269 g
0.23 g
14
Per-100 g values are the amino acid analysis on the USDA record. The serving and per-gram-of-protein columns are arithmetic on those values; they are not a protein quality score.
SampleWhat goal trends look like after a week
109 g
Average per logged day
4 of 7
Days goal met
71%
Complete-protein share
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Sample figures for one made-up week against a 110 g goal, not your data. Red bars met the goal. Your own log fills this in with Premium.
Related
Other seafood by protein per calorie
Swap for more protein per calorie
Crayfish - 20.1 g per 100 kcal, 14.9 g per 3 oz cooked
Conch - 20.2 g per 100 kcal, 33.4 g per 1 cup sliced
Whiting - 20.3 g per 100 kcal, 20 g per 3 oz cooked
Closest in protein per calorie
Halibut - 20.3 g per 100 kcal, 19.1 g per 3 oz cooked
Dungeness crab - 20.3 g per 100 kcal, 19 g per 3 oz cooked
Rockfish - 20.4 g per 100 kcal, 18.9 g per 3 oz cooked
Canned shrimp - 20.4 g per 100 kcal, 17.3 g per 3 oz drained
19.4 g. The 3 oz cooked serving used on this page weighs 85 g and so carries 16.5 g.
How much protein do you get per 100 calories of crab?
20 g. That figure divides its 19.4 g of protein per 100 g by its 97 kcal per 100 g, so it does not depend on serving size.
Is the protein in crab complete?
Yes. The protein in crab supplies all nine essential amino acids in adequate amounts, so it can carry a meal's protein on its own.
What share of the protein Daily Value is one serving of crab?
About 33%. One 3 oz cooked serving has 16.5 g, and the FDA Daily Value for protein is 50 g.
Figures from USDA FoodData Central record #174202 (Crustaceans, crab, alaska king, cooked, moist heat), SR Legacy data. USDA data is in the public domain. Values are the published reference figures for that record, not lab measurements for a specific brand or batch.