As a general guideline it is preferable to have a minimum of two feet around each side of the coffee table and it should be reachable, without standing, from each of the seating areas. Some people also suggest that your coffee table should be no larger than sixty percent of your sofas length. The height that you choose very much depends on what you intend to use it for. Modern coffee tables are often very low; however this may make using it for eating difficult. It is often a good idea to place an item of a similar size and shape to any table that you intend to buy in the room. This will give you a feel for how it will work with the space that you have.
The size of your singular coffee tables is also a very important consideration. If you have larger scale furniture you want your coffee tables to be larger in scale also. A room can look odd and unbalanced if the coffee table is disproportionately larger or smaller than your other furniture. Keeping this in mind you should determine what size coffee table will best fit your space. You don't want to purchase a coffee table only to realize when you get it home that you don't have space for it because it's too big or that you have too much space because it's too small.