Please forgive me, my math skills are poor when it comes to formulas. If someone could either tell me the sq in's or even tell me the formula so I can calculate it out I would appreciate the help. Here is the calculator so I don't have to retype the info. And then a pic of the damper I would like to have on the intake for the fire box. Half guess, half math I think I am close. One other question that probably makes a big difference is when I mount the fire box to the cook chamber, I would like to mount it as low as possible. How do I figure the area for a tear-drop shape. I will be using flat plate for my ends so the fire box will just sit flush to the cook chamber and not actually enter the chamber like seen on a propane tank. And here is what I would like for a damper. I know this is asking alot, so if someone could at least point me in the right direction I would appreciate it greatly.