How much protein is in canned tuna per 100g?

A practical rule of thumb is that canned tuna has roughly 25 grams of protein per 100 grams when drained, with many products falling in the 23 to 29 gram range. Tuna packed in water usually lands toward the higher end after draining, while tuna packed in oil can be similar by weight but often comes with more calories from the oil.

For context, 100 grams is a little more than 3.5 ounces. That means a standard 5-ounce can of tuna can deliver around 30 to 40 grams of protein total, depending on how much liquid is included and how much tuna remains after draining.

Why the number changes between brands and types

Not all canned tuna is identical. Light tuna, albacore tuna, skipjack, and yellowfin can differ slightly in protein and fat content. The biggest practical difference is usually the packing liquid: tuna in water tends to be leaner, while tuna in oil has more calories and fat per 100 grams.

Draining also matters. If a label lists nutrition for the tuna "as packed," the protein-per-100g may look lower than a drained serving because the weight includes water or oil. If you’re tracking macros closely, compare labels for the exact product you buy instead of relying on a generic average.

Is canned tuna a good protein source?

Yes. Canned tuna is a high-quality, complete protein source, meaning it provides all essential amino acids. It is especially useful if you want a lot of protein with minimal prep time.

It can also fit well into muscle-building or fat-loss meals because it is filling and easy to portion. If you’re using canned tuna around workouts, pairing it with carbohydrates such as rice, crackers, potatoes, or fruit can make the meal more balanced.

If you log meals or train at home, Fitnit can also help with workout tracking by counting reps automatically and analyzing form, which can make it easier to keep your nutrition and training consistent.

What else to check besides protein

Protein is the headline, but sodium, calories, and mercury are worth paying attention to. Tuna can be a salty food, especially in flavored or seasoned varieties, so choose lower-sodium options if you eat it often.

Mercury is another reason to vary seafood choices. Health authorities generally recommend mixing tuna with other protein sources like salmon, sardines, eggs, beans, chicken, yogurt, or tofu rather than relying on tuna every day.

If you want the most accurate macro count, use the nutrition facts panel and compare it with the USDA FoodData Central listing for similar products.

Tips

• Check whether the label is for tuna packed in water or oil, and whether nutrition is listed drained or as packaged.
• For a leaner meal, choose tuna in water and drain it well before weighing or logging.
• If you eat tuna regularly, rotate in other protein sources to reduce mercury exposure and keep your diet varied.
• Use a food scale when possible; 100g by weight is more accurate than estimating by can size.
• Watch sodium if you are buying flavored tuna salads or seasoned packets.