There are 416 calories in 100 grams of Soybeans (Mature Seeds). Get full nutrition facts and other common serving sizes of Soybeans (Mature Seeds) including 1 oz and 1 cup. Protein content and RDA percentage, per serving and per 100g, in 12 types of soybeans. The amount of Protein is 43.32 g to 8.47 g per 100g, in soybeans. Soybeans are a plant-based protein powerhouse with 18 grams per 3.5 ounce serving. Plenty of fiber and micronutrients add to their nutrition profile. Nutritions Soybeans, dried per 100 grams. What is what? View the most important nutritional values of soybeans, dried. The overview shows the amounts of kcal, proteins, fats, carbohydrates, vitamins and minerals. The default values for soybeans, dried are shown in 100 grams.