Look at all the food stores you have on hand and divide by the number of people you are planning to save. This will give you an idea how long you can last before starvation sets in. Include pets.
While you're at it, make a chart of how that food supply diminishes with the addition of another mouth, two, three, four.
Understand that your entire food supply can be taken from you by a starving mob. If you survive, you become one of that mob.
Forget about strangers.,....what about family members who did not prepare. Will you take them in? Will you let your immediate family starve to feed
them? Do the math, finite food, infinite hunger.