I did a quick search and didn't find any recent threads - thought I'd share some research I have been doing. Couldn't readily find it in this form. I have a spreadsheet that goes with it - little rough but be glad to post it if anyone is interested.
Whether you buy into the potential for economic collapse, live in hurricaine territory or watch too much Glenn Beck, stockpiling some food is probably a good idea.
With that in mind, and being an engineer - let's talk numbers.
COUNT YOUR CALORIES
An adult needs roughly 1500 calories and up depending on age, size, activity level etc. per day. For purposes of my excercise I used 2000 calories for each adult (we can stand to loose a few pounds anyway!).
Once you have that number target an initial supply: multiply the people you are responsible for times the number of days of supply. Many people are using 6 months these days, not a bad idea to start with a month and work your way up.
Not really any right answer here, it's what you can afford and what gives you comfort. Only wrong answer is to not store anything.
STORAGE FOOD TYPES, STORAGE LIFE, COST PER CALORIE
I looked at three classes of "storage foods"
Freeze dried "emergency foods", originally sold to backpackers
Cost per calorie $0.0139 for basic mix of various #10 cans
In #10 cans, shelf life of 30 years, 7 years in pouches - add water and heat ready to eat, highest cost per calorie. This is in the buy it and forget it category, no need to rotate stock or make part of your routine, just need to try what you store to make sure it is edible. I have been using Mountain House products - not bad but again, expensive.
Canned, jarred and bottled foods
Cost per calorie $0.0042 for a mix of what we eat (third the cost of freeze dried)
Call it two years shelf life, but can actually hold nutritional value long after that at the expense of taste. Not unheard of for canned foods properly stored to be ok to consume 7 years later. 100 year old canned peaches from shipwrecks, although not visually appealing or tasting were found to be ok to eat. This category is your middle of the road. If you want to ensure you don't waste money, you need to either buy what you use or begin using what you buy to keep stock rotated. Don't waste your time buying spaghetti-o's, or other highly prepared food (less bang for the buck) or something you don't normally eat.
Bulk Whole grains
Cost per calorie $0.0027 roughly half the cost of canned and one fifth the cost of freeze dried.
In 6 gallon 45 pound pails represent your biggest bang for the buck.
Whole grain stored in these food grade sealed pails with oxygen removed will last 15 years
Does require purchase of a grain mill to make flour, and work to make food!
Not for everyone, but a good option for folks who don't mind the work or dont have the money.
1. Get a mix of all three balanced for your family, lifestyle and pocketbook. For a family of four, if you can afford to order a truckload of mountain house products for 10 grand, have at it. Other wise, you can get a months worth of canned goods and grains for about the price of a nice revolver ($750)
2. Buy what you eat and eat what you buy (except freeze dried)
3. For freeze dried, #10 cans are cheaper, but buy and try a pouch of what you intend to store
4. Don't forget water!
5. amazon.com has "subscription" options for canned foods so you don't need to rent a truck to do this; cans come well packaged and in an outside box that doesn't announce to the UPS man or the neighborhood that you are storing food. Compared to local prices, there were many items that were significantly less expensive than what we could buy locally. We live in a high cost area so YMMV.
6. Keep it quiet - if you want to show off your food storage, better count the person you show it to under the calorie count above. Your math isn't going to work if you prepare for a family of four but wind up with 8 other hungry people on your doorstep. Your choice here is to carefully educate the people close to you so they too are prepared preferably without exposing your security blanket.
I hope you are never in a situation where you need it. But if you are, I hope you have enough.
Best of luck to you and your family in these trying times.