here is a site with a tank calculator on it. http://www.aquasite.com/index.htm
IMO I think it is a inacurate though.........it says my 150 is 827lbs. (That could be the total weight with a stand) It felt alot lighter than that....mabee I just wanted the tank so bad it gave me supper human strenth to move it in with one of my buddies. Theres no way in heck we could have deadlifted over 400lbs to get it off the ground. I didn't notice any lumps coming out of our stomachs from it.