It has been conventional wisdom that the ideal amount of seating for a home party is one seat for every guest. The hosts of a party would carefully count the number of available seating spaces and compare that to the guest list. If the total of guests exceeded the seating capacity, it would be time to seek some additional chairs. This often involved borrowing some folding chairs, and setting them up inside the party area.

Much depends on the type of entertaining that is being done. A dinner party is an example of an event where sitting needs to be consistent with the guest list. In fact, it is seating and table space that sets the limit of the guest list. A formal dinner party does not work well with some of the guests sitting on the living room couch with their plates in their laps. There are other kinds of events that are much the same as the dinner party. Events where it will be expected that at some time during the duration of the event, everyone will need to be seated at the same time.

A party, even a cocktail party, is a different story. The ideal cocktail party involves a certain amount of circulation. If you plan the party properly, you plan a flow into it. The flow is intended to move the guests from area to area in order to facilitate mingling and interaction between them. If your refreshments are centered in a dinning area, for example, but your party extends into the living room and other areas of the home, the movement of guests to the refreshment area provides this circulation.

When planning a party this way, an excessive number of chairs is the worst possible thing. If every guest is able to find a comfortable chair, they will have a tendency to sit down and put down roots at their chair. Guests will tend to have someone "saving their seat" when they do have to leave it for any reason. They are also more likely to return quickly in order to reclaim their chairs. A number of chairs that is slightly less than the number of guests is also bad. It can easily lead to your party becoming an adult musical chairs game as the guests vie for the available seating. Anyone not able to find a chair begins to feel somehow like a loser.

There is always a need for some chairs. There should be just enough to provide seating for people who might be elderly, or ill, or even have had a bit too much to drink. Outside of this, seating is not needed. It is going to be a better party if everyone is up and moving around. So, it depends on the party and the situation. The answer could be expressed this way: enough seating is enough for the purposes of your entertaining event.