Nutrition Label Calculator

Energy is estimated using the standard Atwater factors: each gram of fat provides 9 kcal, each gram of carbohydrate 4 kcal and each gram of protein 4 kcal. So kcal per 100 g = 9 x fat + 4 x carbohydrate + 4 x protein. The calculator applies the same logic, then scales the result to your portion. These are indicative values; the EU table also allows for fibre and alcohol, which a full label may need to include.

Energy on EU labels is shown in both kilojoules and kilocalories. To convert, multiply kcal by 4.184 to get kJ. The calculator reports both so the per-portion figure matches the dual-unit format required by EU Regulation 1169/2011. As with all outputs, treat the numbers as indicative and check the local regulations that apply.

The per-portion factor is the portion size in grams divided by 100. Each per-100 g value is then multiplied by that factor. For a 150 g portion the factor is 1.5, so a value of 260 kcal per 100 g becomes 390 kcal per portion. The same factor applies to fat, carbohydrate and protein.

Under EU Regulation 1169/2011 the mandatory nutrition declaration covers energy (kJ and kcal), fat, saturates, carbohydrate, sugars, protein and salt, usually expressed per 100 g or 100 ml. This calculator handles energy and the main macronutrients to give you indicative per-portion figures; a compliant label may require additional values and a laboratory or recognised database for accuracy. Always check the current local regulations.

It gives a fast, indicative estimate suitable for menu planning and internal use. For a legally compliant printed label you typically need verified ingredient data and may need values that this tool does not compute, such as saturates, sugars and salt. Always check the regulations in force in your market before publishing nutrition information.