Calories in tuna
Tuna (light, canned in water, drained) contains 86 calories per 100g, with 19.4g of protein, 1g of fat and no carbohydrates. A serving of 1 can, drained (165g) comes to roughly 142 calories.
Calories by serving size
Based on 86 kcal per 100g (light, canned in water, drained).
| 3 oz (85g) | 73 kcal |
|---|---|
| 100g | 86 kcal |
| 1 can, drained (165g) | 142 kcal |
Full nutrition facts
Per 100g, light, canned in water, drained.
| Energy | 86 kcal |
|---|---|
| Protein | 19.4 g |
| Total fat | 1.0 g |
| Saturated fat | 0.2 g |
| Carbohydrate | 0 g |
| Sugars | 0 g |
| Fibre | 0 g |
| Sodium | 247 mg |
| Cholesterol | 36 mg |
| Potassium | 179 mg |
How this fits a day of eating
A drained 165g can of light tuna in water has about 142 calories, around 7% of a 2,000 calorie day, and around 32g of protein. Few foods deliver that much protein for so few calories, which makes canned tuna one of the cheapest ways to raise protein on a tight calorie budget.
Tuna canned in oil is a different food. Drained oil-packed tuna is roughly 190 to 200 calories per 100g, so check the label and log the version you actually ate.
Common questions
How many calories are in a can of tuna?
A standard can of light tuna in water yields about 165g of drained fish, which contains roughly 142 calories and 32g of protein. Can sizes vary between brands and countries, so check the drained weight on the label and multiply it by 0.86 calories per gram for an accurate figure.
Is tuna in water or oil better for weight loss?
Tuna in water is the lower-calorie choice, at about 86 calories per 100g drained, compared with roughly 190 to 200 for tuna packed in oil. Draining oil-packed tuna removes some of the oil but not all of it. If you prefer a richer texture, add a measured teaspoon of olive oil instead.
How much canned tuna is safe to eat per week?
Canned light tuna, usually skipjack, is lower in mercury than albacore. US FDA advice lists canned light tuna as a best choice, with two to three 4 oz servings a week suggested for pregnant or breastfeeding women. Albacore is listed as a good choice, limited to one serving a week for those groups.
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Nutrition values from USDA FoodData Central, FDC ID 173709, per 100g unless stated. Last reviewed 18 September 2026. Calorie needs vary by person.