You like a little elbow room, right? Well, so does everyone else. Think of that when designing a table.
This one is pretty easy, in my opinion — allow 30 inches per person. No need to overcomplicate things. Sure, you can get by with 24 inches per person, especially if your piece is going in a small space, but why not allow more comfort?
So what does this mean in your table design? For a square table, 30 inches will give you a small, four person table…let’s say a card table or a breakfast nook table. A rectangular table at 30 x 60 will allow six people easily… a nice little dining table. A 30 x 90 table (I just usually take it on up to 8 feet) can allow for 10 people.
To complicate things a bit, you may need to adjust if you plan on using large legs — maybe 3 1/2 x 3 1/2 actual dimensions — or if you allow for a large overhang off the ends relative to the legs.
Round tables also complicate things. Stick with the same 30-inch rule (diameter) for a dining/breakfast table. if you want to create a bistro-type table (large enough for a small plate and cup of coffee, for example), knock it down to 24 inches, or even 18 inches. For larger groups of people, add another 14 to 16 inches in diameter for every two people — 44-46 inches for four, 58-62 inches for six, and 72-78 for eight.