Plain tofu is a low-sodium food. A half-cup serving of firm tofu contains roughly 18 mg of sodium, which is less than 1% of the WHO’s recommended daily limit of 2,000 mg. Where tofu gets a reputation for being salty is in how it’s prepared, seasoned, and packaged.
Sodium in Plain Tofu
Raw, firm tofu prepared with calcium sulfate contains about 18 mg of sodium per half-cup (126g) serving. To put that in perspective, a single slice of bread typically has 100 to 200 mg of sodium, and a tablespoon of soy sauce can pack over 900 mg. Plain tofu barely registers on the sodium scale.
Silken tofu tends to be similarly low, though the exact number varies by brand. Extra-firm tofu, because it has less water and more concentrated soybean content per serving, may contain slightly more sodium than softer varieties, but the differences are small. Across all types of plain, unprocessed tofu, sodium content stays well under 50 mg per serving.
Why Some Tofu Tastes Salty
The sodium problem with tofu almost never comes from the tofu itself. It comes from everything around it. Soy sauce, teriyaki glaze, miso-based marinades, and pre-seasoned tofu packages can push sodium levels dramatically higher. A single tablespoon of soy sauce adds roughly 900 mg of sodium to a dish, nearly half the daily recommended limit.
Pre-marinated or flavored tofu sold in grocery stores often contains 300 to 500 mg of sodium per serving, depending on the brand and seasoning. If you’re watching your sodium intake, always check the nutrition label on flavored varieties rather than assuming tofu is universally low-sodium.
Fermented Tofu Is a Different Story
Fermented tofu products are significantly higher in sodium than their plain counterparts. Fermented bean curd, sometimes called preserved tofu or “stinky tofu,” is typically cured in brine or salt-heavy seasoning mixtures. A single 85g serving of spicy stinky tofu can contain around 410 mg of sodium, more than 20 times what you’d find in a comparable amount of plain firm tofu. These products are meant to be used as condiments or flavor accents rather than eaten in large portions, but the sodium adds up quickly if you’re not paying attention.
How Tofu Compares to Other Proteins
When stacked against other common protein sources, plain tofu is one of the lowest-sodium options available.
- Plain firm tofu (1/2 cup): ~18 mg sodium
- Chicken breast, unseasoned (3 oz): ~60 mg sodium
- Canned tuna (3 oz): ~200–300 mg sodium
- Deli turkey (3 oz): ~500–700 mg sodium
- Canned black beans (1/2 cup): ~400–460 mg sodium
For anyone managing blood pressure or following a low-sodium diet, plain tofu is one of the safest protein choices you can make. It gives you a blank canvas that lets you control exactly how much salt ends up on your plate.
Keeping Tofu Low-Sodium
If your goal is to keep sodium low while still making tofu taste good, the key is choosing your seasonings carefully. Reduced-sodium soy sauce cuts the salt by about 40% compared to regular versions. Coconut aminos, a popular soy sauce alternative, contain roughly 90 mg of sodium per teaspoon, which is lower but still adds up across a full recipe.
Acid-based marinades work well without adding sodium. Lime juice, rice vinegar, ginger, garlic, chili flakes, and fresh herbs can all build flavor on tofu without touching the salt shaker. Pressing your tofu before cooking removes excess water, which helps it absorb these flavors more effectively and develop a better texture when pan-fried or baked.
Buying plain, water-packed tofu and seasoning it yourself will always give you the most control. The ingredient list on plain tofu is typically just soybeans, water, and a coagulant like calcium sulfate. If you see sodium-heavy additives on the label, you’re looking at a processed or pre-seasoned product rather than plain tofu.