Cost effective space saving long shelf-life nutrition. When evaluating an Emergency Food Kit please take note of the total number of meals / calories included in the pack. Some suppliers will label a 90-meal emergency food pack as a '3 month supply'. That is only one meal a day! If you are planning for an emergency situation that will last for more than a few days, you should calculate for at least two, ideally three fully-balanced meals per day to sustain activities.
A note on units of energy: in nutritional context a calorie (cal) and kilocalorie (kcal) are equivalent. More information on emergency & survival food