How much gram protein is in 100 g of soybean? A nutritional breakdown

November 26, 2025 •

2 min read

According to USDA data, 100 grams of raw mature soybeans contains 36.5 grams of protein. However, the protein content varies significantly depending on whether the beans are raw or cooked, with a 100g serving of boiled soybeans providing around 16 to 18 grams of protein.

Quick Summary

The protein content of 100 grams of soybeans varies significantly depending on preparation, from approximately 36g when raw to 16-18g when boiled, due to water absorption.

Key Points

Protein Content Varies by Preparation: Raw soybeans contain roughly 36.5g of protein per 100g, while cooked, boiled soybeans contain a concentrated 16-18g per 100g due to water absorption.
A Complete Protein: Soy is one of the few plant-based foods that provides a complete protein profile, containing all nine essential amino acids.
Rich in Nutrients: Beyond protein, 100g of boiled soybeans offers healthy fats, dietary fiber, and a wide array of vitamins and minerals.
Superior Protein Density: Soybeans deliver significantly more protein per serving compared to other common legumes like kidney beans and chickpeas.
Supports Overall Health: The unique compounds in soybeans, such as isoflavones, are linked to benefits for heart health, bone density, and menopausal symptoms.
Versatile for Diets: The protein from soybeans can be consumed in various forms, including whole beans (edamame), tofu, tempeh, and processed protein powders.

Protein Content: Raw vs. Cooked

The amount of protein in a 100g serving of soybean depends heavily on preparation. Raw soybeans, being dry, have a higher protein concentration than cooked soybeans, which absorb water.

Boiled Soybeans

Boiled soybeans swell by absorbing water, diluting the protein concentration. A 100g serving of mature, cooked, and boiled soybeans contains approximately 16.6 to 18.2 grams of protein. This remains a significant amount for a plant-based protein source.

Raw Soybeans

Raw, mature soybeans contain about 36.5 grams of protein per 100 grams. While typically not eaten raw, this figure highlights the nutrient density of the dry bean. Processed soy products often use defatted soy meal, bringing their protein content closer to the raw bean's profile.

A Complete Protein Source

Soybean protein is a complete protein, containing all nine essential amino acids the body cannot produce. This is uncommon for plant-based sources and makes soybeans valuable for vegetarian and vegan diets. Its protein quality is comparable to animal proteins like milk and eggs.

Beyond Protein: Other Nutritional Highlights

Soybeans offer more than just protein. A 100g serving of boiled soybeans also provides:

Healthy Fats: Approximately 9 grams, mainly polyunsaturated and monounsaturated fatty acids.
Dietary Fiber: A good source with 6 grams per 100g.
Vitamins and Minerals: Including vitamin K1, folate (B9), copper, manganese, phosphorus, iron, and potassium.
Isoflavones: Phytoestrogens linked to potential health benefits.

Soybean vs. Other Legumes: A Protein Comparison

Comparing soybeans to other legumes reveals their superior protein density. The table below shows how 100g of boiled soybeans compares to equal servings of cooked chickpeas and kidney beans:


Nutrient (per 100g, boiled)	Soybeans	Kidney Beans (Rajma)	Chickpeas (Chana)
Protein	16.6 g	8.7 g	8.9 g
Fats	9.9 g	0.5 g	2.6 g
Fiber	6.0 g	6.4 g	7.6 g
Calories	173 kcal	127 kcal	164 kcal

Boiled soybeans offer nearly double the protein of cooked kidney beans or chickpeas per 100g.

Health Benefits of Soybeans

Soybeans offer various health advantages due to their nutritional makeup:

Cardiovascular Health: May help lower LDL cholesterol and triglycerides.
Bone Health: Isoflavones might improve bone density.
Menopausal Symptom Relief: Phytoestrogens may ease hot flashes.
Muscle Building: Effective for muscle growth and recovery.
Weight Management: High protein and fiber promote fullness.

Conclusion: The Power of Soybean Protein

The protein content in 100g of soybean depends on preparation, ranging from about 36.5g in raw form to 16-18g when boiled. As a complete protein with healthy fats, fiber, vitamins, and minerals, soybeans are a valuable food source. They provide a dense and versatile protein option, especially for plant-based diets. For more information on soy's role in global food needs, consult the study: Perspective: Soybeans Can Help Address the Caloric and Protein Needs of a Growing Global Population.

Frequently Asked Questions

Yes, cooking affects the protein concentration in soybeans. A 100g portion of raw soybeans has a much higher protein content (36.5g) than a 100g portion of cooked soybeans (16-18g) because the cooked beans have absorbed water, increasing their weight and diluting the protein per gram.

Yes, soybeans are one of the few plant foods that are considered a complete protein source. This means they contain all nine essential amino acids required for human health.

Soybeans have a higher protein content than most other legumes. For instance, a 100g serving of boiled soybeans (16.6g protein) has nearly double the protein of cooked chickpeas (8.9g) or kidney beans (8.7g).

In addition to protein, 100g of cooked soybeans provides healthy fats, approximately 6g of dietary fiber, and essential micronutrients like iron, folate, and potassium.

Consuming soy protein has been associated with several health benefits, including supporting cardiovascular health by lowering bad cholesterol and potentially helping with bone density and menopausal symptoms due to the presence of isoflavones.

Yes, soy protein is an effective source for muscle building and is often compared to whey and other animal proteins for its ability to support muscle protein synthesis and recovery.

Yes, processed soy products like tofu, tempeh, and soy milk can be part of a healthy and balanced diet. They offer a versatile way to incorporate high-quality soy protein and other nutrients. Just be mindful of added ingredients and processing methods.