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Calories in Tuna

Q: How many calories in tuna?

Fresh cooked tuna: 144 calories per 100g. Canned in water (165g): 191 kcal, 42g protein. Canned in oil (165g): ~330 kcal.

Updated July 2026 · Reviewed by CaloriesCalc Team · Source: USDA FoodData Central

144

kcal

per 100g

29.9

Protein

3.2

Fat

0.0

Carbs

Fiber

191

kcal per can in water (165g)

144

kcal per 100g

kcal per oz (28g)

Tuna nutrition facts and calories per 100g

💪29.9g protein per 100g — highest protein fish

🔬Selenium — 102% Daily Value

🧠Vitamin B6 — 61% Daily Value

⚡Potassium — 441mg per 100g

❤️Omega-3 EPA+DHA — 0.27g/100g

⚠️Mercury — limit to 2-3 servings/week

🐟 Calculate Calories for Any Tuna Weight

Weight100g

Nutrition Facts

Per 100g (cooked tuna)

* % Daily Value based on a 2,000 kcal diet.

Quick summary: Tuna contains 144 calories per 100g with 29.9g protein — among the highest protein-to-calorie ratios of any fish. A can in water (165g) provides 42g protein at only 191 calories. Excellent source of selenium (102% DV) and vitamin B6 (61% DV). Mercury content requires monitoring for high-frequency consumption.

Vitamins & Minerals — per 100g

Nutrient	Amount	% Daily Value
Niacin (B3)	18.8mg	117%
Vitamin B12	2.21µg	92%
Selenium	56.3µg	102%
Vitamin B6	1.04mg	61%
Potassium	441mg	9%
Phosphorus	311mg	25%
Magnesium	35mg	8%
Vitamin D	5.7µg	57%
Iron	1.0mg	6%
Zinc	0.77mg	7%

Calories in Tuna by Weight

Weight	Calories	Protein	Fat	Carbs

Macronutrient Breakdown — per 100g

Protein29.9g · 83% of calories

Fat3.2g · 20% of calories

Carbohydrates0.0g · 0% of calories

Canned tuna in water: ~109 kcal/100g. Canned in oil: ~200 kcal/100g. Fresh/cooked yellowfin: ~144 kcal/100g. Albacore (white tuna) has more omega-3 but also more mercury than skipjack (light tuna).

Micronutrient Highlights

💪

Protein

29.9g

60% DV

Highest protein density of any common fish

🔬

Selenium

56.3µg

102% DV

Full daily requirement in one serving

🧠

Vitamin B6

1.04mg

61% DV

Brain health and protein metabolism

⚡

Potassium

441mg

9% DV

Blood pressure and heart function

💊

Vitamin B12

2.21µg

92% DV

Neurological function

⚡

Niacin (B3)

18.8mg

117% DV

Energy metabolism

Tuna Health Benefits

Highest Protein Density of Any Common Fish

Fresh tuna provides 29.9g of protein per 100g at only 144 kcal — a protein-to-calorie ratio of 0.83, rivalling turkey breast (0.89). A can of tuna in water delivers 42g of complete protein at under 200 calories. Tuna protein has a PDCAAS of 1.0 — the maximum score, indicating perfect amino acid balance relative to human requirements.

Selenium — Full Daily Value in One Serving

Tuna provides 56.3µg of selenium per 100g — 102% of the daily value. A single 100g serving completely covers the daily selenium requirement. Selenium is essential for the antioxidant enzyme glutathione peroxidase, thyroid hormone metabolism, and DNA synthesis. Selenium in fish (selenoneine — a unique selenium compound found only in marine animals) has higher bioavailability than selenium in plant foods or supplements.

Vitamin B6 and Brain Health

Tuna provides 1.04mg of vitamin B6 per 100g — 61% of the daily value. B6 is essential for over 100 enzyme reactions, including serotonin, dopamine, and GABA synthesis. High B6 intake is associated with reduced risk of depression, improved cognitive function, and lower homocysteine levels (a cardiovascular risk factor). Tuna is one of the richest dietary sources of B6.

Niacin — 117% Daily Value

Tuna is one of the most concentrated food sources of niacin (B3), providing 18.8mg per 100g — 117% of the daily value. Niacin is essential for over 400 NAD-dependent reactions, including energy production, DNA repair, and cell signalling. Pharmacological doses of niacin are used clinically to raise HDL cholesterol — tuna's niacin content, while not pharmacological, contributes meaningfully to daily intake.

Tuna vs Other Fish — Calorie Comparison

Is Tuna Suitable for Your Diet?

✅

Weight loss

Excellent — highest protein fish

✅

Keto

Yes — zero carbs

✅

Paleo

Yes

✅

Gluten-free

Yes

✅

Diabetic

Yes — zero carbs

✅

High protein

#1 fish for protein

❌

Vegan

❌

Vegetarian

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Frequently Asked Questions

How many calories in tuna?

Fresh cooked tuna: 144 calories per 100g. Canned in water (165g): 191 kcal, 42g protein. Canned in oil (165g): ~330 kcal.

Is canned tuna healthy?

Yes — excellent source of protein, selenium, and B12. Mercury is the main concern. Light tuna (skipjack) has significantly less mercury than albacore (white tuna). 2-3 servings/week of light tuna is safe for most adults.

How much protein in a can of tuna?

A standard can (165g, drained) provides approximately 42g of protein at 191 calories — making it one of the best protein-to-calorie foods available.

Is tuna keto?

Yes — zero carbs. Canned tuna in water is one of the most economical keto protein sources.

Mercury in tuna — how much is safe?

Light tuna (skipjack): up to 3-4 servings/week for adults. Albacore (white tuna): 1 serving/week for adults, avoid for pregnant women and children. The EPA/FDA advises pregnant women to eat 2-3 servings/week of lower-mercury seafood.

Tuna in water vs tuna in oil?

In water: ~109 kcal/100g, ~25g protein. In oil (drained): ~200 kcal/100g. In water is preferable for calorie control. In oil provides additional fat-soluble vitamin absorption.

Sources

Nutrition values from USDA FoodData Central. Not medical advice.