I'm 6'5" - 230lbs and I ride 2.2K miles a year hauling my fat butt back and forth to work.
My "cycle dude" inseam is 37" (with a moderate scrunch factor )
Now if you follow "0.67 * inseam" that says I'm a 62cm-63cm frame but I heard people say once you are "out of the norm" all of the cookbook forumlas are a bit bogus.
What's your inseam? What road frame size fits you? What mtb frame size fits you? What cross frame fits you?
37" - road 64 cm, cross - I'll have to measure it... mtb is a 21" but the seats up a mile and I've got major bar extensions.