This calculator estimates the calories, protein, and fat in any serving of mackerel — raw fillets, cooked portions, or drained canned fish. It is designed for people tracking calories and macronutrients, planning high-protein meals, or simply wondering what that 4-ounce fillet on the dinner plate actually contains. Enter your portion in ounces, grams, or pounds, choose the type and preparation, and the calculator returns immediate totals.
Mackerel is one of the most nutrient-dense oily fish available. A typical 1-ounce serving of raw Atlantic mackerel provides about 58 calories, 5 grams of protein, and 4 grams of fat, while the leaner king mackerel supplies close to 30 calories per ounce. Because different species and cooking methods change the numbers, this tool uses separate profiles for Atlantic, Pacific/Jack, cooked, and canned mackerel.
Results include total calories, protein, fat, and per-ounce values, which makes logging a meal faster and comparing mackerel with other fish much easier.
🐟 Mackerel serving nutrition
Estimate calories, protein, and fat for any portion of mackerel.
How to Use This Calculator
Start by weighing your mackerel on a kitchen scale. For the most accurate portion, weigh it raw before cooking because moisture loss during cooking concentrates nutrients and changes the energy density per gram. If you are using canned mackerel, drain the liquid first and weigh only the fish solids.
- Enter the weight of your portion in the amount box. You can switch between ounces, grams, and pounds using the unit dropdown.
- Select the mackerel type and preparation that matches your meal. The dropdown includes raw Atlantic, cooked Atlantic, raw Pacific/Jack, raw king, and drained canned mackerel.
- Press Calculate to see the total calories, protein, and fat for your portion, plus per-ounce values.
How the Calories Are Calculated
The calculator converts your portion into grams and multiplies by the nutrient values stored for each mackerel profile. The core formula is:
Calories = weight in grams × (kcal per 100 g ÷ 100)
Protein and fat are calculated the same way with their per-100 g values. To get a per-ounce figure, the tool multiplies the per-100 g value by 28.3495 g per ounce and divides by 100.
These nutrient values come from USDA FoodData Central, which lists whole-food composition data for raw and cooked fish. Because fish composition varies with season, diet, and fat content, real mackerel can differ by several percent from reference data.
Reference Nutrition Values Used
The table below summarizes the values used by the calculator. “kcal/100 g” means kilocalories per 100 grams of edible flesh.
| Form | Calories / 100 g | Protein / 100 g | Fat / 100 g | Calories / oz |
|---|---|---|---|---|
| Atlantic mackerel, raw | 205 | 18.6 g | 13.9 g | 58 |
| Atlantic mackerel, cooked | 262 | 23.2 g | 17.3 g | 74 |
| Pacific / Jack mackerel, raw | 158 | 20.1 g | 7.9 g | 45 |
| King mackerel, raw | 105 | 20.8 g | 2.0 g | 30 |
| Canned mackerel, drained | 156 | 21.9 g | 6.3 g | 44 |
Values are rounded to one decimal place and are best treated as starting estimates, especially for wild-caught fish.
Worked Examples
Example 1: 4 oz raw Atlantic mackerel
4 oz × 28.35 g/oz = 113.4 g. Calories = 113.4 × (205 ÷ 100) = 232.5 kcal. Protein = 113.4 × 0.186 = 21.1 g; fat = 113.4 × 0.139 = 15.8 g.
Example 2: 150 g drained canned mackerel
150 g × (156 ÷ 100) = 234 kcal. Protein = 150 × 0.219 = 32.9 g; fat = 150 × 0.063 = 9.5 g. If the can is packed in oil and you don’t drain it, total fat and calories will be higher.
Common Mistakes to Avoid
Don’t confuse raw and cooked weights. A cooked Atlantic mackerel portion has about 74 kcal per ounce because it has lost water during cooking. If you weighed it raw, use the raw profile; if you weighed it after cooking, use the cooked profile.
Watch canned oil. Canned mackerel packed in oil can contain 20–40 additional calories per serving from the oil. Use the drained option and drain well before weighing.
Species matter. King mackerel is much leaner than Atlantic mackerel, so using the wrong profile can change your estimate by almost half. It is also higher in mercury, so frequent consumption should be checked against FDA advice about eating fish.
For meal logging, weigh the cooked portion if you are eating leftovers and choose the cooked profile. For raw meal prep, weigh before freezing or cooking.
Frequently Asked Questions
How many calories are in one ounce of mackerel?
It depends on the type: raw Atlantic mackerel has about 58 kcal per oz, cooked Atlantic about 74, Pacific/Jack about 45, king mackerel about 30, and drained canned mackerel about 44. The calculator uses these per-100 g values to scale any portion size.
Can I use this on a keto or low-carb diet?
Yes. Mackerel contains no carbohydrates, and the oily varieties are rich in protein and fat, so it fits many low-carb, keto, and high-protein meal plans.
Why does cooked mackerel have more calories per ounce?
Cooking removes water, so the same ounce contains more cooked flesh solids and more concentrated protein and fat. The total calories in the whole fillet do not magically increase, but calories per gram do.
How accurate are these numbers?
They are based on USDA reference data and are a good starting point, but mackerel is a wild fish, so its fat content varies with season and location. Read food labels for packaged products and use the calculator as an estimate.
For similar nutrient estimates on another fatty fish, you can use the salmon fat calculator, or track the wider impact of your diet with a body composition calculator.