Nutrition Label Calculator

Package nutrition labels sometimes list values per serving rather than per 100 g, and serving sizes vary widely. The values in this calculator's database are per 100 g representative averages for each food category. Specific brands may differ slightly due to formulation, cooking method, or fat content of the particular cut. For exact values, use the specific food's nutrition facts panel and adjust by gram weight.

Cooking concentrates or dilutes nutrients depending on the method. Boiling leaches water-soluble vitamins into cooking water. Frying adds significant fat calories (oil is absorbed). Grilling or baking minimally changes macronutrient content but changes weight through moisture loss. Protein and fat content per gram of dry weight changes little with cooking; carbohydrate content changes mainly through added ingredients. The database uses representative cooked values where noted.

The Atwater factors (protein: 4 kcal/g, carbohydrate: 4 kcal/g, fat: 9 kcal/g) are standard conversion factors used globally on nutrition labels. They represent average digestibility and metabolizable energy across broad food categories. Fiber is often excluded from carbohydrate calories in some labeling systems (using 2 kcal/g instead of 4) - this calculator uses the standard 4 kcal/g Atwater convention.

Yes, this is a practical tool for estimating the macros in a planned meal before you prepare it. Select the foods you plan to use, enter your intended portions, and check whether the resulting protein, carbohydrate, and fat distribution matches your daily macro targets. Adjust portions or substitute foods as needed. For accurate meal-by-meal tracking in a deficit, weigh all cooked and raw ingredients before eating.