sizing beam for header
We are opening up a wall to get more "open concept" between two rooms. The new opening we want is 9 feet 3 inches. This is on the first floor of a 2 story house, I assume it is a load bearing wall because there is another wall directly above.
I hear anecdotally that a 2 x 8, doubled up, is sufficient for an 8ft span and a 2 x 10, doubled up, is sufficient for up to 10 feet.
Can anyone point me to a table or a calculator or an equation where I can determine what size header I would need using traditional methods, and what I can use if I go with an LVL or some engineered solution? The things I find online are very confusing about live load and dead load and PSF vs PLF and deflection criteria and bearing resistance, etc. I just want a simple beam, supported by 4 x 4s underneath either end. Is a double 2 x 10 enough to hold up my house and meet code? Is a single (or double) LVL that is 7 1/4 tall enough?
I know ultimately it will come down to the building inspector's OK. I just want to be able to be somewhat informed before I talk with him.