As per SMRC condition minimum beam width is 10" , also b/d>=.3 . But my question is there any condition on beam minimum width depending beam length .As per Susil kumar min of ( 50b or 250b^2/d) . So if i choose b=1ft d= 4ft ,maximum span length can be 50 ft. Can any one clarify this issue and give me a few more reference on beam minimum width depending on span . Thanks in advance