Tuna is a lean, protein-packed seafood staple, but its fat content varies dramatically depending on the species and how it's packed. A can of light tuna in water may deliver less than 1 gram of fat per 100 grams, while the same serving canned in oil can contain more than 8 grams. This Tuna Fat Calculator helps you quickly estimate fat grams, calories from fat, protein, and total calories for any portion of tuna — whether you're meal prepping, tracking macros, or just curious about your lunch.
Choose from common canned and fresh tuna varieties, enter your serving size in grams or ounces, and the tool returns a full nutrition breakdown. It also shows the percentage of calories coming from fat, which is useful for low-fat diets, high-protein meal plans, and anyone managing calorie intake. The values are based on standard USDA reference data, so you can rely on them for everyday diet planning.
Use the preset buttons for typical portions like a drained 5-oz can or a 3-oz cooked fillet, or enter a custom amount. The calculator covers canned light and albacore tuna in water or oil, plus fresh yellowfin, bluefin, and skipjack.
🐟 Tuna Fat Calculator
Estimate fat, protein, and calories for any serving of tuna.
How to Use This Tool
Start by selecting the tuna variety and pack that matches what you're actually eating — the dropdown includes canned light and albacore tuna packed in water or oil, plus cooked yellowfin, skipjack, and bluefin, and raw fresh tuna. Each option carries its own average nutrition profile per 100 grams, so choosing the right one matters for an accurate result.
Next, set your serving size. The quick preset buttons cover the most common portions: a standard drained can (about 142 g), a 3-ounce serving (85 g), a convenient 100 g portion, and half a can (about 71 g). If none of those fit, type any value into the serving amount field and pick grams or ounces from the unit dropdown. The calculator converts ounces to grams automatically using 1 ounce = 28.3495 grams.
Finally, press Calculate Fat to see total fat, protein, calories from fat, total calories, and the percentage of calories coming from fat. A step-by-step breakdown appears below the results so you can follow how each number was derived. Use Reset to clear your inputs and return to the default 100 g serving of light tuna in water.
Tip: For canned tuna, always drain it well before weighing. The nutrition values in this tool describe the drained, edible portion — not the liquid in the can, which can add water or oil weight without contributing meaningful protein.
Formula Explained
This calculator is built on average USDA nutrition values expressed per 100 grams of edible tuna. For any serving size, the tool scales those values using simple proportions, so the math is transparent and easy to verify.
Fat (g) = fat per 100 g × serving weight (g) ÷ 100
Protein (g) = protein per 100 g × serving weight (g) ÷ 100
Calories from fat = fat (g) × 9
Total calories = calories per 100 g × serving weight (g) ÷ 100
Fat share (%) = calories from fat ÷ total calories × 100
Fat is converted to calories using the Atwater factor of 9 kcal per gram, the same standard used in nutrition labeling worldwide. The calorie value per 100 g already includes energy from protein as well as fat; tuna contains essentially no carbohydrate, so nearly all remaining calories come from protein at 4 kcal per gram. That is why two tuna varieties can have very different calorie counts while both being high in protein — the difference is almost entirely fat.
Note on averages: The values used here are population averages from the USDA FoodData Central database. Individual cans and fish can vary by season, diet, age, and catch location, but the averages are accurate enough for everyday meal planning and macro tracking.
Worked Examples
Example 1: Canned light tuna in water. Suppose you eat a full drained can weighing 142 g. The per-100 g values are 116 calories, 0.8 g fat, and 25.5 g protein. Fat = 0.8 × 142 ÷ 100 = 1.1 g; protein = 25.5 × 142 ÷ 100 = 36.2 g; calories from fat = 1.1 × 9 = 10.2 kcal; total calories = 116 × 142 ÷ 100 = 165 kcal; fat share = 10.2 ÷ 165 × 100 = 6.2%. A very lean meal — only about 6% of calories come from fat.
Example 2: Albacore canned in oil. For the same 142 g drained serving of white/albacore packed in oil (158 kcal, 7.0 g fat, 22.4 g protein per 100 g), fat = 7.0 × 142 ÷ 100 = 9.9 g; calories from fat = 9.9 × 9 = 89.4 kcal; total calories = 158 × 142 ÷ 100 = 224 kcal; fat share = 89.4 ÷ 224 × 100 = 39.9%. Nearly 40% of the calories come from the absorbed oil — a meaningful difference if you are watching fat intake.
Reference Table
Average nutrition values per 100 g of edible portion, based on USDA FoodData Central. Use these numbers directly in the calculator or as a quick reference when you don't have the tool handy.
| Tuna Variety | Calories (kcal) | Fat (g) | Protein (g) |
|---|---|---|---|
| Light tuna, canned in water (drained) | 116 | 0.8 | 25.5 |
| White/albacore, canned in water (drained) | 128 | 3.0 | 23.6 |
| Light tuna, canned in oil (drained) | 198 | 8.2 | 29.1 |
| White/albacore, canned in oil (drained) | 158 | 7.0 | 22.4 |
| Yellowfin, cooked | 109 | 0.9 | 24.9 |
| Skipjack, cooked | 103 | 1.0 | 22.0 |
| Bluefin, cooked | 184 | 6.3 | 29.9 |
| Fresh tuna, raw | 108 | 0.4 | 23.3 |
To scale any column to a different portion, multiply the per-100 g value by your serving weight in grams and divide by 100 — the same math the calculator performs automatically.
Tips & Best Practices
Getting consistent, reliable nutrition estimates comes down to a few habits.
Weigh tuna after draining, not before. The liquid in a can contributes weight but almost no protein, so weighing an undrained can overstates your actual serving. For oil-packed tuna, you can reduce fat further by rinsing the fish in hot water after draining, though this removes some flavor along with the oil.
Use the right variety for the species. Light tuna is typically skipjack, while white tuna is albacore. They have noticeably different fat and calorie profiles, so don't swap one for the other in your tracking without updating the selection.
Be consistent over time. If you always log the same brand and pack, small variations between cans will average out, and your weekly totals will be far more accurate than if you change assumptions from meal to meal.
Mercury note: Canned light tuna is lower in mercury than albacore or fresh large tuna like bluefin. If you eat tuna regularly, follow the advisory from the FDA or your local health authority about portion limits, especially for children and pregnant women.
Common Questions
Why does tuna packed in oil have so much more fat?
During canning, the surrounding oil is partially absorbed into the fish's flesh. Draining removes some of it, but not all — a measurable amount remains on and inside the fish. That absorbed oil is why oil-packed tuna can show 7–8 g of fat per 100 g while water-packed versions stay under 3 g.
Should I always drain my canned tuna?
If your goal is to minimize fat and calories, yes — drain thoroughly and, for oil-packed tuna, rinse with water. If you are aiming for a higher-fat diet or simply prefer the flavor and texture of oil-packed tuna, keep the oil and account for it in your daily totals. Either choice is valid as long as you are consistent in what you log.
Is fresh tuna a fatty fish?
Most fresh tuna species are quite lean. Cooked yellowfin and skipjack both deliver under 1.5 g of fat per 100 g, with roughly 100–110 calories. Bluefin is the notable exception, reaching about 6 g of fat and 184 calories per 100 g because of its higher oil content. Compared with oily fish like salmon or mackerel, most tuna varieties are considerably leaner.
Why are the label values different from this calculator?
Brands use different lot averages, and some labels report values for the entire contents of the can, including liquid, rather than drained fish. Also, per-serving sizes vary by brand. For the closest match, compare the drained 100 g values rather than the label's serving line. The USDA data used here comes from FoodData Central and represents widely accepted averages.