A cup of cooked beans delivers roughly 14 to 18 grams of protein, depending on the variety. That puts beans in the same ballpark as two large eggs or a serving of Greek yogurt, making them one of the most protein-dense plant foods available.
Protein by Bean Variety
Not all beans are created equal when it comes to protein. Here’s what you get from one cup of cooked beans, based on USDA data:
- Lentils: 17.9 grams of protein, 230 calories
- Black beans: 15.2 grams of protein, 227 calories
- Navy beans: approximately 20 grams of protein (10 grams per half cup)
- Chickpeas: 14.5 grams of protein, 269 calories
- Kidney beans: approximately 14 grams of protein (7 grams per half cup)
Lentils and navy beans sit at the top for common varieties. Chickpeas, while still a solid source, carry more calories per gram of protein because of their higher fat and carbohydrate content. If you’re trying to maximize protein per calorie, lentils are the best pick: about 31% of their total calories come from protein.
Edamame (young soybeans) outperforms all common beans at 18.4 grams of protein per cup of shelled pods. Soybeans are nutritionally distinct from other beans in several ways, including their protein quality, which is closer to animal protein.
Canned vs. Dried Beans
The difference is negligible. One cup of cooked dried black beans has 15.1 grams of protein, while the same amount of canned black beans has 14.5 grams. That half-gram gap holds across other varieties too. The canning process doesn’t meaningfully alter protein, fat, carbs, or fiber content. Choose whichever fits your schedule and budget. The main nutritional difference with canned beans is sodium, which you can reduce by rinsing them before use.
How Your Body Uses Bean Protein
Protein quality matters as much as quantity. Scientists measure this with a score called the PDCAAS, which rates how well a protein supplies the essential amino acids your body needs, on a scale from 0 to 1. Common beans (black, kidney, pinto) score around 0.61. Chickpeas and lentils score about 0.52. For comparison, soybeans score 0.91, and animal proteins like eggs and dairy hit 1.0.
The reason beans score lower is that they’re low in sulfur-containing amino acids, specifically methionine and cysteine. These are the “limiting” amino acids in almost all common beans. On the other hand, beans are rich in lysine, an amino acid that grains lack. This is exactly why rice and beans is such a nutritionally smart combination: grains fill the gap beans leave, and beans fill the gap grains leave. You don’t need to eat them in the same meal for this to work. As long as you’re eating both over the course of a day, your body gets the full range of amino acids it needs.
How Beans Compare to Other Protein Sources
A cup of cooked black beans (15.2 grams of protein, 227 calories) delivers its protein alongside 15 grams of fiber, complex carbohydrates, iron, and folate. A chicken breast of similar calorie count would give you roughly 40 grams of protein but almost no fiber or carbs. Beans are not a one-to-one protein replacement for meat, but they bring a package of nutrients that animal sources don’t.
If you’re relying on beans as a primary protein source, you’ll want to eat larger or more frequent servings than you might expect. Hitting 50 grams of protein from black beans alone would take a little over three cups. Most people eating a plant-forward diet combine beans with grains, nuts, seeds, and sometimes dairy or eggs to reach their daily protein target without needing massive portions of any single food.
Getting the Most Protein From Beans
Cooking method doesn’t significantly affect protein content, but a few practical choices can help you get more from your beans. Soaking dried beans before cooking reduces compounds called phytates and tannins that can interfere with how well your body absorbs protein and minerals. Sprouting beans takes this a step further, improving digestibility even more.
Pairing beans with a grain at some point during the day (rice, bread, corn tortillas, pasta) completes the amino acid profile. Adding a source of vitamin C, like tomatoes or lime juice, helps your body absorb the iron that comes along with the protein. These small moves don’t change the grams on the label, but they change how much of that protein your body actually puts to use.