Octopus is a lean, protein-rich seafood that fits naturally into calorie-conscious and high-protein meal plans. But how many calories in a slice depends heavily on two things: how thick the slice is and how the octopus was prepared. Raw octopus contains roughly 82 kcal per 100 g, while cooked octopus concentrates to about 164 kcal per 100 g because moisture is lost during cooking. This calculator takes those factors into account so you can estimate calories per slice quickly and accurately.
Whether you are meal-prepping a seafood salad, building a poke bowl, or simply tracking your daily intake, this tool gives you calories, protein, fat, and carbohydrates for any number of slices. Just enter your slice count, slice weight, and preparation method, then hit Calculate. You will also get a per-slice macro breakdown and a quick view of where the calories come from.
🍽️ Serving Details
How This Calculator Works
Octopus calorie density changes dramatically with moisture loss. Raw octopus is about 80–82% water, so 100 g of raw octopus delivers only ~82 kcal. When you boil or grill it, water evaporates and the same 100 g portion now contains roughly twice the solids — and roughly 150–164 kcal. This calculator starts from standard per-100 g reference values and scales them to your exact serving size using this simple relationship:
Total kcal = (slices × grams per slice) ÷ 100 × kcal per 100 g
Macronutrients are scaled the same way: grams of protein, fat, and carbs = (total grams ÷ 100) × per-100 g values.
The tool then divides the total by your slice count to show the per-slice energy contribution, and it breaks total energy down into the calories coming from protein, carbohydrates, and fat using the standard Atwater factors of 4 kcal per gram for protein and carbs and 9 kcal per gram for fat. That breakdown is particularly useful if you are following a macro-targeted diet or simply want to understand why octopus is so protein-dense relative to its calorie cost.
Worked Examples
Example 1: Standard cooked slice
You have 4 slices of boiled octopus, each weighing 20 g. Total weight = 80 g. Using the cooked value of 164 kcal/100 g: (80 ÷ 100) × 164 = 131 kcal. Per slice = 131 ÷ 4 ≈ 33 kcal. Protein ≈ (80 ÷ 100) × 29.8 ≈ 23.8 g, which is an excellent protein yield for such a modest calorie load.
Example 2: Light raw carpaccio slice
You slice raw octopus thinly to 10 g per slice and use 6 slices. Total weight = 60 g. Using the raw value of 82 kcal/100 g: (60 ÷ 100) × 82 ≈ 49 kcal. Per slice ≈ 8 kcal. This shows why raw preparations feel lighter than boiled octopus salads — the extra water weight has not yet been concentrated.
These examples also illustrate why weighing matters: a hand-cut slice is rarely a consistent unit. A 10 g difference between slices can change a 4-slice snack by 30–50 kcal depending on the cooking method. Using a kitchen scale for the first few servings helps you calibrate your eye for future portions.
Reference Data: Octopus Nutrition Per 100 g
The values below are based on common food-composition entries for octopus and are useful for meal planning. Always check the label or a specific database entry if you have a brand-tested product.
| Preparation | Calories (kcal) | Protein (g) | Fat (g) | Carbs (g) |
|---|---|---|---|---|
| Raw | 82 | 14.9 | 1.0 | 2.2 |
| Cooked / boiled | 164 | 29.8 | 2.1 | 4.4 |
| Grilled / roasted | 150 | 27.0 | 2.0 | 3.0 |
Note that these are estimates. If you cook octopus with oil, butter, or a marinade, the added fats can raise the calorie count well beyond the plain-cooked figures. The grilled option in the calculator assumes minimal added oil.
Tips for Accurate Tracking
- Weigh the slice, don't guess. A slice can range from 8 g to 30 g. A digital kitchen scale is the single best investment for calorie tracking.
- Match the preparation to your food. If you boiled octopus at home, select cooked. If you are eating it raw in ceviche or sushi, select raw. For grilled tentacles with visible oil, use the grilled option and consider adding a small oil allowance.
- Use cooked weight with cooked values. Because octopus loses water when cooked, weighing raw and cooked portions gives different gram amounts. Pick the value that matches the state you weighed.
- Account for sauces and glazes. Olive oil, lemon butter, soy-based glazes, and mayonnaise-based dips add calories rapidly. A single tablespoon of olive oil is about 120 kcal, more than many entire slices of cooked octopus.
- Leverage the macro breakdown. Since octopus is very protein-dense, this tool can help you fit it into high-protein meal plans while keeping fat and carbs in check.
Frequently Asked Questions
Is octopus low in calories?
In its raw or lightly prepared form, yes. Raw octopus provides around 82 kcal per 100 g, placing it in the same low-calorie range as white fish. The calorie count climbs once cooked because water loss concentrates protein and other nutrients.
How much protein is in one slice of cooked octopus?
For a standard 20 g slice of boiled octopus, protein is about (20 ÷ 100) × 29.8 = 5.96 g. That is roughly 12% of the daily protein requirement for an average adult, depending on your body weight and goals.
Can this calculator handle octopus salads or mixed dishes?
It estimates plain octopus calories only. Vegetables, dressing, and other ingredients need to be added separately. If you are also tracking other lean proteins, you might find our chicken nutrition calculator a helpful comparison for building balanced meals.
Why does cooked octopus have more calories per 100 g than raw?
Cooking removes water but not calories. Since 100 g of cooked octopus represents more solid matter than 100 g of raw octopus, the energy density increases. If you track by weight before cooking, use raw values; if you track after cooking, use cooked values.
For authoritative nutrition values, USDA FoodData Central is a reliable free reference: fdc.nal.usda.gov. You can also read more about octopus as food on Wikipedia.