Measure your room, and subtract 8' from each measurement. ( If there is furniture we can't see on a wall, take that into account, as well). The result is the largest table that should be placed in your space.

Thank you for your response, but because this area is open to 3 other living areas, I don't know how to measure the space. Plus, I'm mathematically challenged! Here is a photo of a sheet folded on the floor in an approximate 60" circle. (The rug is 8x10 1/2"). Would a 60" round table be too large?

Another picture of the space.

A 60" round table will normally seat 6 people, and be a tighter squeeze for 8, depending on the chair. This is assuming a pedestal base where nothing is there to get in the way of people's legs. Your sheet on the floor at 60" seems to fit well.

Thank you for your input. It is scary to custom order something and it not be the correct size! I don't want the table to look too small for the space, but I also don't want it to be crowded. I'm hoping to be able to use the chairs I have now. I've always wanted a round table! I think I'm going to go for it! Thanks again.

Just a little comment on the side. The French believe that dining table should be just a little tight to create a more intimate atmosphere. I think they might be right. Imagine if everyone feels like they are at a conference table. So don't worry about seating eight people where there ought to be six. Just get the table with a pedestal, so there won't be any obstruction for the feet. And the chairs have to be around 18" wide. The math is here as follows: 60" x 3.14 = 181 : 8 = 22.5". So the space per person on the table's circumference is 22.5" which is a little less than a standard 24". So to allow for elbows you need chairs no more than 18" wide. And that would accommodate 8 people. For six you can go standard.