To determine total calories desired, begin by plotting the patient's weight on an appropriate growth chart. Use the actual weight if the patient is at or below the 50th percentile for weight and length. Use the 50th-percentile-adjusted weight if the patient is above the 50th percentile. Remember to correct for prematurity up to age 2 years. Next use the age and appropriate weight on the recommended guidelines to calculate the total desired daily calories. Note there are different guidelines for critical and non-critically ill patients. Finally calculate the protein calories using the formula below. Total protein Kcal = 4 cal x gm protein/kg x weight in kg Example: 30 kg patient to receive 2 gm/kg/day protein protein Kcal = 4 x 2 gm/kg x 30 kg = 240 Kcal