My Preparing to Prepare non-fiction work attempts to walk the 'uninitated' through the process of disaster/disruption/preparedness planning with an basic education and a simplified approach. (Don't worry, there's plenty of stuff in there for the 'intiated' as well.) To aid me in keeping all of the information as concise as possible, I've broken the book down into three parts based on the duration of the event.
In sticking with a 'basics' theme for the uninitiated, I expose the reader to some of the things they might prepare for and provide examples. For example, I grew up in the southeast US. This area is generally hit by 3-5 hurricanes per decade. This means our family, and just about everyone else's family, needed to be prepared in the event a hurricane was headed toward us. The duration for a hurricane related event was usually 7-14 days depending on how close it came to us. As a result, my parents kept enough food and water on hand for a family of 6 given their self imposed two-week duration. This inventory was added to the inventory of batteries, charcoal, firewood, dog food, kerosene, spare propane tanks, etc.
However, back in the late 70's and early 80's, we didn't have the glut of preparedness food suppliers and manufacturers to choose from like we do today. Everything was either in a can or was frozen. Freeze dried anything barely existed. Now, because most of it was canned, it also meant that the sheer weight of it all prohibited us from doing anything other than 'sheltering in place'.
As I continue to do my research and writing for the non-fiction work, I am coming across something I find to be a bit disconcerting. Namely, some of the food suppliers that are offering one-week, one-month, three-month, six-month, one-year supplies of emergency food are misrepresenting the number of servings that it will provide. And by that I mean, the supplier will state that their 6-month supply of food is "Over 500 servings!" Another will state something like, "That's 510 servings!"
Sounds impressive... except when you apply some basic math.
1 person X 3 servings a day X 180 days (6 mos) = 540 servings
Here's my warning/advise: Do your self a favor and make sure that the supplier you are considering is using the correct numbers for the duration you are planning for -OR- you adjust your purchase to account for the full number of servings desired. How much would it suck to have to be one that has to tell their family/group that they are going to run out of food a week, a week and half sooner than expected.
Hopefully, you are growing food at that point and it won't be that taxing, but people do strange things.
Anyway, to aid you in this endeavor, I've constructed these handy tables.
Each table breaks down the number of total servings needed by multiplying the three variables together ('Servings per Day per Person', 'Family Size', and 'Duration of Disturbance').
For example, you have a family of 5 that you want to feed 3x a day for 3 months. Go to the third image above, go to the 'Family Size' row of 5, slide your finger to the right to the '90 (3 months)' column. There you will discover that this fictional family of 5 would need a minimum of '1350' total servings in order to make it the full three months.
Most of the suppliers do generally allocate for a 2000 calorie diet in their calculations, but not all of them. So keep an eye on the quoted calorie count too.