Each table style and size has varying seating capacities.
Round table size seating capacity.
If your guests will be seating for long periods of time like for a formal dinner go with the smaller number of people for example only put 8 at a 60 inch round.
A 36 round table will take 3 to 4 chairs.
As a rough general rule every 24 of table edge length will accommodate one chair.
You will need the extra space for the formal table settings.
For example a 42 x 72 table will accommodate 8 chairs.
48 inch round 4.
That seating capacity could change considerably depending on what size of person will be seated at the table.
72 inch round 6 seats 10 12 adults.
With two leaves.
How to determine table seating capacity for table top sizes.
Be sure that the chairs arms are low enough to slide beneath and not bump into the table.
If you have a low apron find chairs that seat at a comfortable height.
In general seating capacity can be broken down as follows.
60 inch round 5 seats 8 10 adults.
46 48 inch round tables can seat 6 60 inch round tables can seat 8 and 72 inch round tables can seat 10.
Add casters to sofa legs if you need to raise the seat height.
If you use a sofa or bench for seating at a long table choose one with a high enough seat.
Additionally you would need a fairly large round table to accommodate a small number of guests.