The formula for figuring up the cubic foot volume for a log is by using Huber's formula, which is pretty simple. Cu ft volume= .005454 * (D^2) * L D=diameter at midpoint of log and L=log length. The midpoint diameter on these logs is 16", so the cu ft volume is 22.34.
Don't like that formula? Smalian's formula is cu ft = .002727 * (SD^2+LD^2) * L SD=small end diameter, LD=large end diameter and L=log length. Volume now is 22.69.
When we developed the log weight formula, we used Huber's formula. I figured it would be easier to put in one diameter easier than two, and then there's the problem of butt flare and rookie log scalers.
The log weights are for green wood and come from the Forestry Handbook put out by the Society of American Foresters. Weights were put into the calculator so you can see how heavy they are saying certain woods weigh.
The disclaimer was put in there for 2 reasons. One was that from our experience, log weights vary and you won't get two logs of the same species to weigh exactly the same with the exact same volume. Too many variables.
The other reason was that we didn't want someone to come back on us with one of those "well, you said it weighed this much and it was heavier and you broke our equipment" type of arguement.