I keep my tobacco in totes. Jars, tins, cans and mylar by the tote-fulls. Totes cannot be easily calculated which can lead to a fudge factor. The fudge factor in this equation for my calculation is called TAD.
I had it calculated that seven totes would be enough for my lifetime. I then started questioning my calculation which led me to "I just might live a TAD bit longer than I expect".
I'm currently up to nine totes now. Five years from now and re-questioning my calculations and my life expectancy a TAD bit longer, I'm pretty sure it will be eleven totes.