1. Find the serving size on the can

Start with the Nutrition Facts panel. Most tuna cans list protein per serving and servings per can. A common can may have about 2 servings, while some pouch or larger cans have more.

Check whether the label is based on drained tuna or the whole can contents. That difference can change the protein total a lot, especially for tuna packed in water.

2. Multiply protein per serving by the number of servings

A simple example: if one serving has 13 grams of protein and the can contains 2 servings, one can has about 26 grams of protein. Two cans would then have about 52 grams.

For many standard 5-ounce cans of tuna, two cans often land in the 40-60 gram range. Exact totals vary by brand and tuna style, so use your label when accuracy matters.

3. Watch the tuna type and packing liquid

Light tuna, albacore tuna, tuna packed in water, and tuna packed in oil can all have slightly different nutrition profiles. Oil-packed tuna may have more calories and fat, while protein is usually still high.

If you track macros, log the tuna exactly as eaten. Draining the liquid, mixing with mayo, or adding cheese will change the final protein-to-calorie ratio.

4. Avoid these common mistakes

Don’t assume every can is the same size. Some are 2.5 ounces, some are 5 ounces, and some larger cans contain multiple servings.

Don’t confuse drained weight with total can weight. Also, don’t use protein estimates from a different tuna product unless the serving size matches closely.

If you want an easier way to stay consistent with meals and workouts, Fitnit can help you track exercise reps with your phone camera, but for food, the Nutrition Facts label is still the best source.

Tips

• Use the exact serving size and servings per can from the label.
• For meal prep, log tuna by drained amount if the label uses drained values.
• Add protein from mayo, yogurt, or cheese separately if you mix tuna into a salad.
• When in doubt, round down slightly to avoid overestimating protein.
• If you eat tuna often, check mercury guidance too, especially for albacore.