Nutritional Value Calculator

Multiply the per-100 g value by the serving weight divided by 100. For example, if a food has 200 kcal per 100 g and your serving is 150 g: 200 × (150 / 100) = 300 kcal. The calculator does this for all macronutrients automatically.

Nutritional values per 100 g are printed on the product label under "Nutritional information". For home-cooked meals, use a nutrition database such as USDA FoodData Central, Open Food Facts or a Polish database like IŻŻ (Institute of Food and Nutrition).

According to standard nutritional values: 1 g of protein = 4 kcal, 1 g of fat = 9 kcal, 1 g of carbohydrates = 4 kcal, and 1 g of alcohol = 7 kcal. The calculator uses these Atwater factors to break down calorie sources.

Total carbohydrates include dietary fibre. Net carbohydrates (used in low-carb and keto diets) = total carbohydrates − dietary fibre. Fibre is not fully digested and contributes minimal calories. Enter total carbohydrates from the label for standard calculations.

Add up the raw ingredient weights, enter the per-100 g values for each ingredient separately, then sum the results. Alternatively, weigh the finished dish, divide total nutrients by total dish weight, and multiply by your serving weight.

Always match the weight to the nutritional data. If label values are for raw food, weigh raw. If values are for cooked food, weigh cooked. Cooking changes the water content, so 100 g raw chicken and 100 g cooked chicken have different calorie counts.

EU law allows a tolerance of ±20% on nutritional label values. Actual values depend on the variety, growing conditions, storage and cooking method. For most dietary purposes this margin is acceptable, but for medical nutrition therapy, more precise measurements may be needed.

General guidelines: carbohydrates 45–65% of calories, fat 20–35%, protein 10–35%. For muscle building, protein is often increased to 1.6–2.2 g/kg body weight. For weight loss, higher protein (up to 30%) helps preserve muscle mass. Individual needs vary — consult a dietitian.

Yes. Heat can destroy some vitamins (especially vitamin C and B vitamins). Frying adds fat. Boiling can leach water-soluble nutrients into the water. Roasting concentrates nutrients by removing moisture. Nutritional databases usually provide values for both raw and cooked versions.

Yes. Enter the values for each food you eat, noting the serving weight. Sum up calories and macros across all meals to compare against your daily target. For effective weight management, aim for a calorie deficit of 300–500 kcal/day below your total daily energy expenditure (TDEE).