Sizing a beam?

Building a barn and would like to build a loft. The loft is only 10' deep 16' wide. Using 40psf live load, 10 psf dead load, I get 200 plf LL and 50 plf DL, if I run joists perpendiclar to the 16' beam. So the question is what size 16' wood beam. No LVL's or engineered beams, just dimensional lumber, 2-ply 3-ply, whatever is needed. Depth is no problem.

And if any one knows of any span tables for dimensional lumber used as beams. I have one, but it doesn't go up to 16'.

Thank you.