Lobster is one of the leanest seafood proteins, but the fat picture changes the moment butter enters the meal. A 100 g serving of cooked Northern (Maine) lobster contains roughly 0.9 g of total fat and only about 0.2 g of saturated fat. Spiny lobster is slightly richer, and adding a pat of melted butter can multiply the fat content several times over.
This calculator separates fat from the lobster meat itself and fat from any butter you add, so you know exactly what is on your plate. Choose your portion size in grams, ounces, pounds, or cups, pick the lobster type, and select how much butter you use for dipping. The results show total fat, saturated fat, calories from fat, and Daily Value percentages.
Whether you are tracking macros, planning a low-fat meal, or just curious about the difference between plain steamed lobster and a butter-heavy feast, this tool gives you a quick, realistic estimate.
🦞 Lobster Fat Calculator
Estimate total fat, saturated fat, and calories from fat in cooked lobster — including any butter you dip into.
Spiny lobster contains slightly more fat than Northern lobster.
per serving, including added butter
| Fat from lobster meat | — |
|---|---|
| Fat from added butter | — |
| Saturated fat | — |
| Calories from fat | — |
| Daily Value (total fat) | — |
| Daily Value (saturated fat) | — |
How the Fat Estimate Works
The calculator converts your serving size to grams and then applies fat values for cooked lobster meat, which are based on USDA FoodData Central records. Northern/Maine lobster contains about 0.9 g of total fat per 100 g and 0.16 g of saturated fat per 100 g. Spiny lobster (rock lobster) contains about 1.5 g of total fat and 0.28 g of saturated fat per 100 g. For butter, the calculator uses standard salted butter values of 11.5 g total fat and 7.3 g saturated fat per tablespoon.
Formula: total fat = (lobster meat grams × lobster fat per 100 g ÷ 100) + butter fat. Saturated fat = (lobster meat grams × saturated fat per 100 g ÷ 100) + (butter fat × 0.635). Calories from fat = total fat × 9 kcal/g. Daily Value percentages use FDA reference values of 78 g total fat and 20 g saturated fat for a 2,000-calorie diet.
The calculator assumes the lobster is cooked by steaming or boiling with no additional oil. If you sauté lobster in butter or oil, add those fats separately. The cup option uses 145 g per cup of chopped cooked meat, a practical average for meal planning. Results are rounded to two decimal places, which is sufficient for everyday nutrition tracking.
Reference Data
| Food | Serving | Total fat | Saturated fat | Calories |
|---|---|---|---|---|
| Northern / Maine lobster, cooked | 100 g | 0.9 g | 0.16 g | 89 kcal |
| Spiny / rock lobster, cooked | 100 g | 1.5 g | 0.28 g | 112 kcal |
| Salted butter | 1 tbsp (14 g) | 11.5 g | 7.3 g | 102 kcal |
| Clarified butter / ghee | 1 tbsp (14 g) | 12.7 g | 7.9 g | 112 kcal |
| Whipped butter | 1 tbsp (10 g) | 8.0 g | 5.1 g | 72 kcal |
Worked example: Steamed Northern lobster with one tablespoon of melted butter.
Serving: 113 g (about 4 oz) of lobster meat. Lobster fat = 0.9 g/100 g × 113 g = 1.02 g. Butter fat = 11.5 g. Total fat = 12.52 g. Saturated fat = (0.16 × 113 ÷ 100) + (11.5 × 0.635) = 0.18 + 7.30 = 7.48 g. Calories from fat = 12.52 × 9 = 112.7 kcal.
Common Mistakes to Avoid
- Using raw lobster values instead of cooked meat values. Cooking changes water content and makes the fat values appear higher per gram of raw product.
- Forgetting to include butter or oil used during cooking. Basting, sautéing, or finishing with oil adds fat that this calculator cannot guess for you.
- Assuming all butter has the same fat content. Whipped, light, or plant-based butter spreads contain less fat per tablespoon than standard stick butter.
- Misreading Daily Value percentages. The 78 g total fat and 20 g saturated fat references are for a 2,000-calorie diet; your personal DVs may differ.
Tips for Lower-Fat Lobster Meals
Serve lobster with lemon juice, cocktail sauce, or a small amount of drawn butter in a separate dish so each bite carries less fat. Removing the tomalley and roe can also reduce occasional richness, although they are not counted as meat in this tool.
If you love the buttery flavor, try a smaller amount of a stronger-flavored fat, like a garlic-herb butter, or use a brush to coat the meat lightly rather than dipping. You can also replace part of the butter with a reduced-sodium broth or white wine reduction.
Frequently Asked Questions
Is lobster really low in fat?
Yes, cooked lobster meat is very lean. Most of the fat in a typical lobster meal comes from melted butter, butter sauces, or mayonnaise-based sides. A plain 100 g portion of Northern lobster has under 1 g of fat.
Why are there different values for Northern and spiny lobster?
Spiny lobster, also called rock lobster, naturally contains more fat and calories than Northern/Maine lobster. The species, diet, and harvest location all influence the exact numbers. The calculator gives practical averages based on USDA data.
Does cooking method (steaming vs. boiling) change the fat content?
Steaming and boiling add no fat to the meat itself. Broiling or grilling with butter basting will add fat. Poaching in a butter-rich court bouillon will also add fat. Choose 'no added butter' in the calculator and add your cooking fat separately if needed.
Do the values include the tomalley?
The tomalley (the greenish digestive gland) is not included in the fat values used here. It is rich in fat and cholesterol, so if you eat it, the total will be higher. The FDA advises caution with tomalley due to potential contaminants in some waters.
Are these values suitable for medical diets?
Use this calculator as an estimate, not a medical tool. For clinical nutrition advice, consult a registered dietitian. You can compare results with the USDA FoodData Central database at fdc.nal.usda.gov.