1) Start with the tuna type

The first step is to identify what kind of tuna you have. Different tuna products do not all have the same protein content. A 100g portion of raw tuna steak, canned tuna in water, and tuna packed in oil can each land at slightly different numbers.

As a practical rule, 100g of tuna is usually a high-protein serving. For many common tuna products, expect roughly 23 to 30g of protein per 100g. If you want the most accurate number, check the label or look up the exact product in USDA FoodData Central.

2) Measure the right weight

Weigh the tuna in the same form you plan to eat it. That means raw if you are logging it raw, or drained if you are eating canned tuna after removing the liquid. Water, oil, and added sauces can change the final weight and make your protein estimate look wrong.

If you do not have a scale, use the nutrition label serving size as your backup. For canned tuna, the label often lists protein per serving and may specify whether the serving is drained. That is usually more reliable than guessing by eye.

3) Convert the label or database value to 100g

Once you have the protein amount for the serving, convert it to a 100g basis. For example, if a 70g drained serving gives 17g of protein, you can estimate about 24g per 100g by dividing 17 by 70 and multiplying by 100.

This is the easiest way to compare tuna with other foods. It also helps you track intake consistently, especially if you switch between canned tuna, tuna steaks, and ready-to-eat tuna packets.

4) Watch the common mistakes

The biggest mistake is mixing up raw weight with cooked or drained weight. Tuna loses or gains water depending on how it is prepared, so the same fish can show different numbers on the scale.

Another common error is assuming all tuna is identical. Albacore, skipjack, yellowfin, and bluefin can differ slightly, and oil-packed tuna will not track the same as tuna in water. For the cleanest macro count, use the exact product entry or label.

Tips

• Use a food scale when you can; 100g is much easier to track than a guessed portion.
• Log tuna in the same state it is measured: raw, drained, or cooked.
• Check whether the can says 'drained weight' or 'as packaged' before entering macros.
• If you eat tuna often, save the exact food item in your tracker so your entries stay consistent.
• For home workouts, Fitnit can help count reps automatically and check form with your phone camera, which makes it easier to match higher-protein meals with a steady training plan.