There's no definitive answer to this question since it will depend on the size of the patio conversation set itself and the amount of space you have available in your outdoor area. However, as a general rule of thumb, you should allow for at least 2-3 feet of space around the perimeter of the set so that people can move freely and comfortably. If your set includes a table, you'll also need to factor in additional space for chairs to be pulled out and moved around. Ultimately, it's best to err on the side of caution and give yourself plenty of room to work with. That way, you can be sure that everyone will have a great time relaxing and enjoying the conversation!