There are several great advantages to this site:
1.) It helps you calculate what you need based on your current family; so, if you have young children, you can prepare for their food intake now and not what you'd need to prepare for if they were adults.
2.) You can easily update your family and instantly see what you need, so every year you can add to your food storage appropriately as your family grows.
3.) Your inventory is all saved online, so no need to worry about tracking your food storage on paper, then losing it (as I did) Just make you sure you update it if you are using your food storage, so you keep track of what you use (unless, of course, you replace it).
The only disadvantage to this site is that they list their products, so you have to enter everything according to their product line. But, it's pretty easy to substitute what you have in terms of their product line.