Every 100 kcal of peanut butter brings 3.7 g of protein. On that measure it ranks 52nd of the 54 legumes in this database and 550th of all 796 foods on the site. Measured by weight instead, its 21.9 g per 100 g ranks 8th in its group.
Around 15% of the calories in peanut butter come from protein, so it is more of an energy food than a protein food. It contributes to a day's protein total, but the bulk of what it delivers is energy rather than amino acids - treat it as a contributor alongside a denser source, not as the protein in a meal.
By weight, fat outweighs protein in peanut butter: 49.5 g of fat per 100 g against 21.9 g of protein, a ratio of 0.4 to 1.
Set against refried beans, another legume entry in the database, a serving carries about 0.6 g more protein (refried beans has 6.4 g per 1/2 cup).
It is an incomplete protein on its own; pairing it with other plant foods across the day covers the full range of essential amino acids. The serving quoted here is measured by volume at 32 g, and it covers about 14% of the 50 g FDA Daily Value for protein.
Serving sizes
Protein in common portions of peanut butter
Protein and calories in Peanut butter for 100 g, the site serving and USDA household portions.
Portion
Weight
Protein
Calories
100 g
100 g
21.9 g
588 kcal
2 tbsp (serving used here)
32 g
7 g
188 kcal
1 cup
258 g
56.5 g
1517 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 peanut butter
The nine essential amino acids in Peanut butter, per 100 g, per serving and per gram of protein.
Amino acid
Per 100 g
Per serving
mg per g protein
leucine
1.53 g
0.49 g
70
lysine
0.672 g
0.22 g
31
valine
0.773 g
0.25 g
35
isoleucine
0.608 g
0.19 g
28
threonine
0.518 g
0.17 g
24
phenylalanine
1.19 g
0.38 g
54
methionine
0.262 g
0.08 g
12
histidine
0.55 g
0.18 g
25
tryptophan
0.228 g
0.07 g
10
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.
21.9 g. The 2 tbsp serving used on this page weighs 32 g and so carries 7 g.
How much protein do you get per 100 calories of peanut butter?
3.7 g. That figure divides its 21.9 g of protein per 100 g by its 588 kcal per 100 g, so it does not depend on serving size.
Is the protein in peanut butter complete?
No. On its own, the protein in peanut butter is short of at least one essential amino acid; other protein sources across the day fill the gap.
What share of the protein Daily Value is one serving of peanut butter?
About 14%. One 2 tbsp serving has 7 g, and the FDA Daily Value for protein is 50 g.
Figures from USDA FoodData Central record #174294 (Peanut Butter, smooth (Includes foods for USDA's Food Distribution Program)), 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.