Calories in Tuna Fish: Complete Nutrition Guide & Data
Tuna fish packs an impressive 19 grams of protein into just 85 calories per 100-gram serving—making it one of the leanest protein sources you can eat. Last verified: April 2026.
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Whether you’re meal prepping, counting macros, or simply trying to understand what’s in your lunch, tuna delivers exceptional nutritional density. What makes tuna particularly valuable isn’t just its calorie count; it’s the remarkable protein-to-calorie ratio that makes it a staple for anyone serious about their diet.
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Executive Summary
At 85 calories per 100 grams, canned tuna represents one of the most efficient protein sources available. You’re getting nearly 22% of those calories from pure protein, with virtually zero carbohydrates and minimal fat. The macronutrient profile is strikingly lean: 0.94 grams of fat and just 0.08 grams of carbs per serving. This makes tuna exceptionally flexible—it works equally well in high-protein diets, keto meals, or balanced nutrition plans.
Beyond the basics, tuna delivers critical micronutrients that many people overlook. A 100-gram serving provides 2.57 micrograms of vitamin B12 (essential for nerve function and red blood cell formation), 1.67 milligrams of iron (important for oxygen transport), and 176 milligrams of potassium (crucial for heart health). The vitamin B6 content at 0.32 milligrams supports metabolism and brain development. These aren’t trivial amounts—they’re meaningful contributions to daily micronutrient needs.
Main Data Table
| Nutrient | Amount | Unit |
|---|---|---|
| Calories | 85 | kcal |
| Protein | 19.0 | g |
| Total Fat | 0.94 | g |
| Carbohydrates | 0.08 | g |
| Fiber | 0 | g |
| Vitamins & Minerals | ||
| Calcium | 18 | mg |
| Iron | 1.67 | mg |
| Magnesium | 23 | mg |
| Potassium | 176 | mg |
| Vitamin A | 17 | mcg |
| Vitamin D | 1.2 | mcg |
| Vitamin B6 | 0.32 | mg |
| Folate | 4 | mcg |
| Vitamin B12 | 2.57 | mcg |
| Vitamin K | 0.2 | mcg |
| Vitamin C | 0 | mg |
Per 100g serving of canned tuna fish. Data source: USDA (verified April 2026)
Breakdown by Preparation Method
The nutritional profile we’ve outlined reflects canned tuna, which represents the most common form people consume. Here’s how different preparation methods compare:
| Preparation Method | Calories (100g) | Protein (g) | Fat (g) |
|---|---|---|---|
| Canned in water (drained) | 85 | 19.0 | 0.94 |
| Canned in oil (drained) | ~145 | 19.0 | ~7 |
| Fresh, cooked | ~130 | 21.5 | ~4.5 |
| Raw | ~132 | 21.5 | ~4.6 |
Notice something interesting? Canned tuna in water contains fewer calories and less fat than fresh tuna—counterintuitive, but true. The reason is processing: much of the fat renders out during canning. If you’re specifically hunting for the leanest option, water-packed is your winner.
Comparison to Similar Fish & Proteins
How does tuna stack up against other popular fish and protein sources? Here’s the breakdown:
| Food Item | Calories (100g) | Protein (g) | Fat (g) | Carbs (g) |
|---|---|---|---|---|
| Tuna (canned in water) | 85 | 19.0 | 0.94 | 0.08 |
| Salmon (cooked) | 206 | 22 | 12 | 0 |
| Cod (cooked) | 82 | 17.9 | 0.7 | 0 |
| Tilapia (cooked) | 96 | 20.1 | 1.7 | 0 |
| Chicken breast (cooked) | 165 | 31 | 3.6 | 0 |
Tuna in water ties with cod for leanest option by calorie count, but what sets tuna apart is the complete amino acid profile and the B12 content. Salmon delivers more omega-3 fatty acids (which tuna also has, though in smaller quantities). Chicken breast has more total protein, but tuna achieves its protein density in fewer calories—a meaningful distinction for calorie-restricted diets.
Key Factors Affecting Tuna’s Nutritional Profile
1. Canning Liquid Makes a Real Difference
Whether tuna is canned in water or oil directly impacts fat content. Tuna packed in water (which is our reference data) contains just 0.94 grams of fat. The same fish canned in oil jumps to roughly 7 grams of fat per 100 grams, boosting calories from 85 to around 145. This isn’t a judgment—oil-packed tuna provides more omega-3s and may taste better to some people—but it’s an important distinction when counting macros.
2. Processing Reduces Fat Content Compared to Fresh
Fresh or raw tuna contains approximately 4.6 grams of fat per 100 grams and runs about 130-132 calories. The canning process, which involves heat and moisture loss, renders some fat and reduces the final product’s caloric density. This is why canned water-packed tuna is often the leanest option available.
3. Vitamin B12 Content is Exceptionally High
At 2.57 micrograms of B12 per 100 grams, tuna provides more than 40% of the daily value (assuming a 6 mcg daily requirement). This matters significantly for vegans considering adding fish to their diet, and for anyone concerned about B12 absorption as they age. This is a major nutritional advantage that tuna holds over plant-based proteins.
4. Iron is Easily Absorbed (Heme Iron)
The 1.67 milligrams of iron in tuna isn’t just any iron—it’s heme iron, which your body absorbs far more efficiently than non-heme iron from plants. While the amount seems modest, your body will actually utilize most of it. Women of childbearing age and people at risk for anemia should note this advantage.
5. Zero Carbs and Fiber Mean True Keto-Friendly Status
With 0.08 grams of carbs and zero fiber, tuna qualifies as genuinely keto-compliant. No hidden carbs, no glycemic impact. This purity is rare among prepared foods and makes tuna especially valuable for low-carb dieters who tire of eating only meat and eggs.
Historical Trends in Tuna Nutrition Data
Tuna’s nutritional profile has remained remarkably stable over the past decade. USDA databases show minimal changes in macronutrient composition since the mid-2010s, which suggests either exceptional consistency in how canned tuna is produced or that standardized canning methods are highly optimized.
What has changed: consumer awareness and labeling. Fifteen years ago, many canned tuna products didn’t distinguish between water-packed and oil-packed on nutrition panels; consumers had to check ingredients. Today, the distinction is standard. Additionally, pressure from health-conscious consumers has led some manufacturers to offer more tuna packed in water or in alternative liquids like vegetable broth.
The one trend worth monitoring: increasing interest in premium, fresh-frozen tuna options, which command higher prices but allow consumers to control cooking methods and added ingredients more precisely.
Expert Tips for Using Tuna Effectively
Tip 1: Rinse Canned Tuna to Further Reduce Sodium
Our data focuses on macronutrients and micronutrients, but sodium is worth mentioning. Canned tuna typically contains substantial sodium (around 300-500mg per 100g depending on the brand). Rinsing drained tuna under cold water for 30 seconds reduces sodium by roughly 30-40% without meaningfully affecting protein or other nutrients.
Tip 2: Pair With Carbs to Optimize Protein Absorption
While tuna’s low-carb profile is great for certain diets, consuming it with some carbohydrates—whole grain bread, rice, or legumes—actually enhances amino acid absorption and utilization. The carbs trigger insulin, which helps drive amino acids into muscle cells. A tuna sandwich with whole wheat bread optimizes this dynamic better than tuna alone.
Tip 3: Rotate Tuna With Other Fish for Mercury Balance
Tuna contains some methylmercury. While a few servings per week is safe, consuming nothing but tuna daily over years can cause accumulation. Rotate with lower-mercury options like salmon, cod, or sardines. The FDA recommends 2-3 servings of fish weekly; varying your selection ensures you get tuna’s benefits without mercury concentration risk.
Tip 4: Buy Albacore Sparingly if Mercury is a Concern
Our data reflects canned light tuna (skipjack species). If you buy albacore (white tuna), mercury levels are roughly 3x higher. For most people, this isn’t a problem, but pregnant women, nursing mothers, and young children should prioritize light tuna.
Tip 5: Freeze Fresh Tuna for 7+ Days Before Eating Raw
If you eat fresh tuna raw (sushi, sashimi), the FDA recommends freezing it at -4°F for 7 days minimum to eliminate parasites. Home freezers are typically around 0°F, so this requires deliberate freezing. This isn’t a nutrition point, but it’s essential food safety information for tuna consumers.
FAQ Section
Q: Is 85 calories for tuna fish accurate for all brands?
A: Yes, with minor variation. Our data comes from USDA standard reference data for canned light tuna in water (drained). Most major brands—Bumble Bee, Starkist, Geisha, store brands—align closely to this 85-calorie figure. The variance you’ll see is typically ±2-3 calories. However, if your tuna is canned in oil, expect 140-160 calories instead. Always check your specific brand’s label; premium or flavored varieties may add calories through added oils or other ingredients.
Q: How much tuna can I safely eat per week?
A: The FDA recommends 2-3 servings of fish per week (a serving is 3-4 ounces or about 85-113 grams). For canned light tuna specifically, you can safely eat 2-3 cans per week without mercury concerns. If you’re pregnant, nursing, or feeding young children, stick to 1-2 cans weekly. Albacore tuna should be limited to 1 can per week for those groups. Men and non-pregnant women face minimal mercury risk even with higher consumption, but exceeding 5-6 cans weekly isn’t necessary given nutritional redundancy.
Q: Does tuna have enough protein to replace chicken?
A: Gram-for-gram, chicken breast edges ahead (31g vs 19g per 100g). But per calorie, tuna is superior. If you’re working with a 2000-calorie daily budget, 300 calories of tuna gives you 57 grams of protein, while 300 calories of chicken gives you 56 grams. The margin is negligible. Nutritionally, you can absolutely replace chicken with tuna; the practical reasons you might not are cost, taste preference, and mercury considerations. Use tuna as your primary protein 2-3x weekly, chicken the rest.
Q: What’s the difference between light and white canned tuna nutritionally?
A: Light tuna (skipjack) has roughly 85 calories, 19g protein, and lower mercury. White tuna (albacore) has approximately 100-110 calories, 19-20g protein, but nearly 3x the mercury. The macronutrient difference is negligible; the mercury difference is significant. Unless you have a strong taste preference for white tuna, light tuna is nutritionally superior for regular consumption due to safety margins.
Q: Can tuna help with muscle building given its protein content?
A: Absolutely. With 19 grams of complete protein (containing all 9 essential amino acids) in just 85 calories, tuna is excellent for muscle building. It’s especially useful for people in a caloric deficit who need protein without excess calories. The amino acid leucine content is solid, which triggers mTOR signaling—important for muscle protein synthesis. To maximize muscle gains, pair tuna with resistance training and consume it 2-4 times weekly as part of a protein-adequate diet (1.6-2.2g protein per kg of body weight daily).
Conclusion
Tuna fish at 85 calories per 100 grams represents an exceptional nutritional bargain. You’re getting nearly a quarter of your daily protein in one small serving while maintaining minimal caloric overhead. The vitamin B12 content, heme iron, and complete amino acid profile make tuna nutritionally dense in ways that pure calorie counting misses.
Choose water-packed canned tuna for the leanest option, rotate it with other fish species to manage mercury exposure, and don’t hesitate to use it as a cornerstone protein in virtually any diet style—keto, high-protein, low-carb, or balanced macronutrient approaches all benefit from tuna’s profile. Whether you’re prepping meals for the week or building a single meal, tuna delivers consistent, reliable nutrition in a convenient, shelf-stable format.
The data speaks clearly: if you’re looking for maximum protein with minimum calories and excellent micronutrient support, canned tuna in water should be a regular part of your rotation.
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