I found this great food storage calculator at;
LDS Food Storage Calculator
As I mentioned previously LDS has alot of knowledge on preparedness and many survival food stores main customers are members of LDS who are looking for a year supply of food.
Fortunately the calculator allows you to input decimals for number of people. If you want to know how much for for one person for 3 months, just enter 0.25 into the number of people box and select calculate.
Now as readers of my blog know that for disaster preparedness for most of us, freeze dried food is the better choice.
Most people do not have the time or inclination to start storing staples listed on the site and spending 4-5 hours a day cooking with them regularly while you use up and replenish your storage. Eating one year old food all the time does not appeal to me nor is it necessary. However some may have a lifestyle that supports using stored staples and that is great for them.
Some however may not be able to afford the amount of freeze dried food and MRE they desire to be prepared. There is also some value in diversifying your food storage. So you may want to consider some stored staples that you can reasonable consume and replenish without it going bad and throwing it out.
So the LDS food calculator is a good tool for your calculations. Please note however that you should be accustomed to the food diet that the staples will provide as many survival experts agree a significant change in diet can cause severe health problems under stress in a disaster or desperate time.
I did a calculation on one year for a family of 4 with children over 7 years. The results were ;
Total Grains 1200 lbs
Total Fats 52 lbs
Total Legumes 240 lbs
Total Sugars 240 lbs
Total Dairy 300 lbs
As you can see foods with the water in them are quite heavy. With freeze dried food 98% of the water is removed and can either be stored separately or gathered from rainwater over a year, there is much more flexibility and portability options. The calculation on the website indicated only 56 gallons which way off, you will need a ton of water to prepare and cook these food staples.
Freeze dried food as a survival food is a better choice for most.