It is an absolutely great tool for understanding how long the food you have will last you. You provide ages and genders for the people you are storing for, from which it calculates your total daily caloric requirements. It’s pre-populated with many common long term storage foods – Freeze Dried, Mountain House, rice, etc – as well as with everything from Emergency Essentials catalog. You provide your inventory of each of these items (plus anything else you want to add), and it calculates total calories stored, and how long it will last. Additionally, it allows you to order from EE (good marketing!), and shows the effect of the purchase in your storage plan.
I did a very quick, off the top of my head estimate of what I have stored while experimenting with the tool. It returned half a million calories, which it estimates will last my family for 3 months. I plan to properly update my inventory in the next couple of weeks, and will see what the tool thinks of that.
Overall, I’m impressed. Added bonus, it’s free to use!
Edit: More thorough inventory of just my long-term storage items puts me closer to 620,000 calories / 115 days!