A standard 5-ounce can of tuna packed in water contains about 120 calories, while the same size can packed in oil jumps to around 280 calories. That’s a significant difference driven entirely by the packing liquid, so which type you grab off the shelf matters more than you might expect.
Water-Packed vs. Oil-Packed Tuna
The packing medium is the single biggest factor in how many calories end up in your can. Water adds essentially zero calories, so what you’re eating is nearly pure protein. Oil, on the other hand, more than doubles the calorie count. Even after draining, oil clings to the fish and stays in the can’s crevices, so you can’t fully remove it.
If you’re tracking calories for weight loss or meal planning, water-packed tuna is the leaner option by a wide margin. Oil-packed tuna does have a richer flavor and softer texture, and the added fat can help with absorbing fat-soluble vitamins. But if your priority is keeping calories low while maximizing protein, water-packed wins easily.
Light Tuna vs. White Tuna
The label on your can will usually say either “chunk light” or “solid white,” and these come from different species with different nutritional profiles. Light tuna is typically skipjack (sometimes yellowfin), while white tuna is always albacore.
In a 3-ounce serving packed in water, the numbers break down like this:
- Light tuna (skipjack): 73 calories, 17 grams of protein
- White tuna (albacore): 109 calories, 20 grams of protein
Albacore is a fattier fish, which explains the higher calorie count. It also delivers more omega-3 fatty acids. A 3-ounce portion of albacore provides roughly 500 to 1,000 milligrams of EPA and DHA (the two omega-3s linked to heart and brain health), while light tuna in water provides about 200 to 500 milligrams per serving.
Full Nutritional Profile
A full 165-gram can of light tuna packed in water, drained, contains approximately 191 calories, 42 grams of protein, and just 1.4 grams of fat. There are zero carbohydrates and zero sugar. That protein-to-calorie ratio is one of the best you’ll find in any food, which is why tuna is a staple for anyone trying to hit high protein targets without excess calories.
Keep in mind that most nutrition labels on cans list a “serving” as 2 ounces (56 grams), which is less than half the can. If you eat the whole can in one sitting, as most people do, you need to multiply the label numbers accordingly. A 5-ounce can contains roughly 2.5 of those listed servings.
Watch the Sodium
Standard canned tuna with salt added can contain 360 milligrams of sodium per can, which is about 16% of the recommended daily limit. That adds up quickly if you’re eating tuna regularly or pairing it with other salty ingredients like soy sauce, pickles, or bread.
“No salt added” varieties are widely available and taste nearly identical, especially once you mix in your own seasoning. If you’re making tuna salad with mustard, lemon, or other flavorful additions, you likely won’t notice the difference. Choosing the low-sodium version gives you more control over your total intake for the day.
Mercury and How Often to Eat Tuna
The FDA classifies canned light tuna (skipjack) as a “Best Choice” for mercury levels, meaning you can safely eat two to three 4-ounce servings per week. Albacore (white tuna) falls into the “Good Choice” category, with a recommendation of no more than one 4-ounce serving per week due to its higher mercury content.
For children, serving sizes scale with age: about 1 ounce for ages 1 to 3, 2 ounces for ages 4 to 7, and 3 ounces for ages 8 to 10. Sticking with light tuna for kids keeps mercury exposure lower while still providing excellent protein and omega-3s.
Quick Calorie Reference by Can Type
- 5 oz light tuna in water: ~120 calories
- 5 oz light tuna in oil: ~280 calories
- 3 oz white albacore in water: ~109 calories
- 3 oz light skipjack in water: ~73 calories
- Full 165g can, light tuna in water: ~191 calories
The variation comes down to three things: the species of tuna, whether it’s packed in water or oil, and how much of the can you eat. For the lowest calorie option with the most protein per bite, a can of chunk light skipjack in water is hard to beat.