Tuna is one of the most popular lean protein sources, but the calories can vary a lot depending on whether it is canned in water, packed in oil, or eaten fresh. This Tuna Calories Per Ounce Calculator helps you quickly estimate the calories, protein, and fat in any serving size — from a 3-ounce sushi slice to a full 6-ounce grilled fillet.
Just pick the tuna type that matches what you are eating, enter your portion in ounces, and the tool converts it to grams, then calculates the nutrition breakdown for you. It is ideal for meal preppers, athletes tracking protein, and anyone counting calories or building a healthy meal plan. Because the tool shows both total and per-ounce values, you can compare options at a glance and make informed choices at the grocery store or dinner table.
🐟 Choose your tuna
📏 Serving size
📊 Estimated nutrition
Enter a serving size and calculate.
Nutritional Values by Tuna Type
The calorie content of tuna depends largely on whether it is canned in water or oil, and whether the packing liquid is drained. The table below gives typical values for 100 g (about 3.5 oz) of edible tuna flesh, based on USDA FoodData Central reference data.
| Tuna type | Calories per 100 g | Protein per 100 g | Fat per 100 g |
|---|---|---|---|
| Canned light tuna in water, drained | 116 kcal | 25.5 g | 0.8 g |
| Canned white / albacore in water, drained | 128 kcal | 20.1 g | 2.5 g |
| Canned light tuna in oil, drained | 198 kcal | 26.5 g | 9.7 g |
| Canned white / albacore in oil, drained | 214 kcal | 21.1 g | 14.2 g |
| Fresh yellowfin tuna, raw | 109 kcal | 24.4 g | 0.9 g |
| Fresh bluefin tuna, raw | 144 kcal | 23.3 g | 4.9 g |
| Fresh skipjack tuna, raw | 103 kcal | 22.0 g | 1.0 g |
Canned values refer to drained solids. Actual label numbers can vary by brand, liquid, and how thoroughly the fish is drained.
How the Calculation Works
The calculator uses a simple proportion. First it converts your serving from ounces to grams: 1 oz = 28.35 g. Then it applies the selected tuna type’s nutrition per 100 g to your exact gram weight:
total calories = (calories per 100 g × your grams) ÷ 100
The same formula is used for protein and fat. Because gram weight is proportional to calories, using grams directly is more accurate than relying on a generic '3 oz serving' label, especially if your portion is a little over or under.
If you want to verify the base numbers yourself, search for the specific product under USDA FoodData Central; many brand entries are also listed there.
Worked Example: Canned Light Tuna in Water
Let's say you use half a small can of light tuna in water and it weighs 3 oz after draining. Enter 3 in the calculator, select canned light in water, and you get:
Calories = (116 × 85.05) ÷ 100 = 99 kcal
Protein = (25.5 × 85.05) ÷ 100 = 21.7 g
Fat = (0.8 × 85.05) ÷ 100 = 0.7 g
That single serving gives roughly 21.7 g of protein for under 100 calories, which is why tuna is a classic choice for people who want to increase protein without increasing fat or carbohydrates. A 5 oz serving would provide about 165 kcal and 36 g of protein.
Water-Packed vs Oil-Packed Tuna
The biggest calorie difference in tuna comes from the packing liquid. When tuna is canned in oil, the fish absorbs some of that oil before draining, so even a well-drained portion contains substantially more calories and fat. The table shows this clearly: light tuna in water has 116 kcal per 100 g, while light tuna in oil has 198 kcal per 100 g.
Oil-packed tuna still has more monounsaturated fat and can be useful if you are trying to add healthy fats to your day. Many people prefer its richer flavor and moister texture. If you are counting calories, choose water-packed tuna, or drain and rinse oil-packed tuna before eating to reduce the added fat. For a closer look at the fat component, try the Tuna Fat Calculator.
Pro Tips for Accurate Tracking
- Weigh tuna after draining when you are tracking a canned product. The label on a 5 oz can refers to the total contents, including water or oil; the drained tuna itself usually weighs only 3.5 to 4 oz.
- For raw fresh tuna steaks, weigh raw if possible. Cooking removes moisture, so the cooked weight will be lighter and the calories will appear more concentrated per gram.
- If you eat sushi, remember that a hand-cut slice of tuna varies in thickness. Weigh several slices together and divide to get a more reliable average per piece.
- Use the same scale and the same draining routine each time. Small variations in retained liquid can shift your calorie estimate by 10–20 calories per serving, which adds up over a week.
- Round to the nearest whole calorie in your food diary, but keep protein and fat to one decimal place for better macro tracking.
Frequently Asked Questions
Is canned tuna as healthy as fresh tuna?
Both are excellent sources of protein, B vitamins, selenium, and omega-3 fatty acids. Canned light tuna in water is lower in calories and fat than many fresh varieties; fresh bluefin is richer and higher in fat. Mercury guidance applies to all tuna, but canned light tuna generally has less mercury per serving than albacore or large fresh tuna.
Why do nutrition labels sometimes show a different calorie number?
Labels are based on the manufacturer's specific product, including the exact fish species, chunk size, and packing liquid. Our calculator uses USDA standard reference values, so it will be close but not identical to a particular brand's label. Check the label when you have it and use the calculator for meals when you don't.
How much tuna can I safely eat each week?
Advice varies by age and whether the tuna is light or albacore. Because albacore and fresh bigeye tuna are higher in mercury, the FDA recommends limiting them. For current guidance, see the FDA advice about eating fish. The calculator can help you track calories while you plan safe portion sizes.
Should I track tuna raw or cooked for fresh steaks?
Use the raw weight for the most consistent tracking, because the amount of water lost during cooking depends on doneness, thickness, and cooking method. If you only have cooked weight, estimate about 100 to 110 kcal per 100 g for lean cooked yellowfin, and 150 to 170 kcal per 100 g for cooked bluefin, depending on how much fat remains.