Not all soy foods are equal when it comes to carbohydrates. A cup of cooked soybeans delivers around 10 grams of carbs, while firm tofu contains under 3 grams per 100-gram serving. Whether you're following a low-carb diet, managing blood sugar, or simply tracking macros, knowing exactly how many carbs are in your favorite soy foods helps you plan meals with confidence.
This soy carbs calculator takes the guesswork out of the math. Choose a soy product, enter your portion size in grams or ounces, and get instant totals for total carbohydrates, dietary fiber, and net carbs. It's useful for anyone who eats tofu, tempeh, edamame, soy milk, or soy yogurt and wants accurate macro numbers.
The tool also shows a mini breakdown so you can see the calculation step by step. Pair it with your favorite nutrition app, or use it to compare soy foods side by side.
How to Use This Calculator
Using the calculator takes about ten seconds. Start by selecting the soy product that matches what you are eating from the dropdown menu. The tool includes the most common soy foods: steamed edamame, cooked soybeans, firm and soft tofu, tempeh, unsweetened and sweetened soy milk, and plain soy yogurt. Next, enter your serving size in grams or ounces. A typical serving is 100 grams, which is roughly 3.5 ounces, but the calculator accepts any positive value.
Press Calculate and the tool returns three values:
- Total carbs — the full carbohydrate content in the serving you entered.
- Fiber — the indigestible carbohydrate portion that is not fully absorbed.
- Net carbs — total carbs minus fiber, often used in low-carb and keto meal planning.
You can also tap a quick-fill button to load a common serving size instantly, or use the Copy result button to paste the numbers into your food diary.
Why Soy Carbs Vary So Much
Soy foods start from the same humble bean, but processing changes the nutritional picture dramatically. Whole soybeans and edamame retain the fiber-rich outer layer and the natural carbohydrates of the bean. A 100-gram serving of cooked soybeans contains roughly 9.9 grams of total carbs, of which around 6 grams are dietary fiber. That leaves only about 3.9 grams of net carbs.
Edamame is similar, with about 8.9 grams of total carbs and 5.2 grams of fiber per 100 grams. These whole-soy options are genuinely low in digestible carbs, which is why they are popular in low-carb and vegetarian meal plans.
Tofu is a different story. To make tofu, soybeans are soaked, blended, and strained to produce soy milk, and most of the fiber is left behind in the pulp (okara). That removes a large share of the carbohydrates as well. Firm tofu therefore contains only about 2.8 grams of total carbs and under 1 gram of fiber per 100 grams. Soft tofu, made with a higher water content, is even lower. Tempeh, made from fermented whole soybeans, sits between the two — it keeps more of the bean's fiber than tofu but still goes through processing.
Liquid soy foods add another layer of variation. Unsweetened soy milk typically has around 3.3 grams of total carbs per 100 ml or 100 grams, while sweetened versions can contain nearly double that because of added sugar. Plain soy yogurt may also contain added thickeners or sweeteners, so it is always worth checking the nutrition label.
Total Carbs vs Net Carbs
Total carbohydrates include starch, sugars, and dietary fiber. Fiber is a carbohydrate, but your body does not break it down into glucose the way it processes sugar and starch. For this reason, many people subtract fiber to get net carbs: Net carbs = total carbs − fiber.
For whole soy foods, this subtraction matters a lot. In cooked soybeans, fiber makes up more than half of the total carbs, so net carbs are less than 4 grams per 100 grams. In tofu, the difference is much smaller because tofu is naturally low in both total carbs and fiber. The calculator always shows both numbers so you can choose which measure fits your approach.
Reference: Common Soy Foods
The table below lists average values per 100 grams. Actual values can vary by brand, recipe, and preparation method, so treat them as a useful starting point rather than a laboratory result. These figures are based on typical values from USDA FoodData Central.
| Soy Food | Total Carbs (g) | Fiber (g) | Net Carbs (g) |
|---|---|---|---|
| Edamame, steamed | 8.9 | 5.2 | 3.7 |
| Soybeans, cooked | 9.9 | 6.0 | 3.9 |
| Tofu, firm | 2.8 | 0.9 | 1.9 |
| Tofu, soft | 1.9 | 0.3 | 1.6 |
| Tempeh | 9.4 | 1.8 | 7.6 |
| Soy milk, unsweetened | 3.3 | 0.6 | 2.7 |
| Soy milk, sweetened | 6.0 | 0.6 | 5.4 |
| Soy yogurt, plain | 4.5 | 0.7 | 3.8 |
If you are comparing soy foods to other legumes, you might also like the bean carbs calculator or the edamame fiber calculator.
Worked Examples
Let's walk through a couple of realistic scenarios so you can verify the calculator on your own.
You cook 120 grams of tempeh for a stir-fry. Tempeh contains roughly 9.4 grams of carbs per 100 grams, so the math is:
Total carbs = (9.4 ÷ 100) × 120 = 11.28 g
Fiber = (1.8 ÷ 100) × 120 = 2.16 g
Net carbs = 11.28 − 2.16 = 9.12 g
You serve 150 grams of steamed edamame in the pod (edible portion weight). Edamame has about 8.9 grams of carbs per 100 grams:
Total carbs = (8.9 ÷ 100) × 150 = 13.35 g
Fiber = (5.2 ÷ 100) × 150 = 7.80 g
Net carbs = 13.35 − 7.80 = 5.55 g
If you weigh edamame with the pods, remember that the pods are not edible and will overestimate your serving size. Weigh the shelled beans instead.
Frequently Asked Questions
Are soy carbs good or bad for a low-carb diet?
It depends on the food. Whole soybeans and edamame are relatively low in net carbs because so much of their carbohydrate is fiber. Firm tofu is also low in carbs, which makes it a favorite on low-carb and keto meal plans. Sweetened soy milk and soy yogurt can contain added sugar, so those are the ones to check carefully.
Should I count net carbs or total carbs?
Most carb-tracking apps use total carbs by default. If you are following a keto or very low-carb plan, you may prefer net carbs. The calculator shows both so you can use whichever number fits your approach. For guidance, see our net carbs calculator.
Why do the numbers differ from the label on my package?
Food manufacturers use slightly different recipes, and some products are enriched with additional fiber or sweeteners. The values in this calculator come from typical USDA reference data for unflavored, plain soy foods. When exact accuracy matters, use the nutrition facts panel on the package and enter your own values.
Does cooking change soy carbs?
Cooking can change water content and weight, which changes the carbs per gram. The total amount of carbohydrate in the food remains roughly the same, but a water-heavy preparation like boiled tofu will have fewer carbs per 100 grams than the same tofu eaten raw. If you are tracking precisely, weigh prepared food after cooking and match it to a cooked-food reference.