Despite the large number of enteral and parenteral nutrition solutions available, it is still the responsibility of the attending physician to determine the patient’s individual requirements. They must make a selection of solutions to be used and dose them in such a way that the previously determined requirements for the essential ingredients water, carbohydrates, amino acids, and fat (and thus the energy content) are covered as completely as possible. At the same time, however, overdosing must also be avoided. In principle, this is possible “with paper and pencil” and a pocket calculator, but the time required quickly exceeds the capacity of the medical staff in an intensive care unit. An Excel-based solution could be designed to carry out the very simple calculation steps quickly, display the results clearly, and print them out in a practical form.