Ark You Ready is a site with a lot of helpful information on it! I like to use this Calculator when trying to track my food storage. You may not store all of the items but it will be helpful for some of the items you do store!
When trying to figure an entire years worth, I print out one blank one so I can calculate what I have and fill it in. And then I print out one after I have added in my family numbers. You can start small with a three month supply and write it into a blank form by dividing the full years total by 4. You get the idea! I use this about twice a year every spring and fall to keep tabs on my total food storage! Hope it helps!
Another Calculator can be found HERE if you want to try it, I believe they are very similar if not the same!