Beam Sizing for Wall Span

I need assistance in determining the size of a beam for a 6.5-foot open wall span. The beam will support one floor above and is located in an inside wall. The floor joists above run in the same direction as the wall.

Requirements:
- Structural engineering knowledge
- Experience with beam calculations
- Familiarity with building codes

Ideal Skills:
- Structural engineering degree
- Previous beam sizing experience
- Detail-oriented and precise

Please provide your qualifications and a brief overview of your approach.