Most witches will make the circle nine feet in diameter. Ask them why and you will get many different answers. Some will say the number nine relates to the Goddess, some that nine is the wish number, some that it is the mathematical product of three squared (Triple God and Triple Goddess etc.).
The nine-foot circle (for whatever reason) is actually an ideal size as it gives pleant of room to work spells and magick. However, not everyone is going to have a nine-foot circular space available.
Those that live in houses or apartments with small rooms will definitely have a problem finding the space. Although there is nothing wrong with casting the circle outdoors (even a small yard can usually accommodate it in size), there is the problem of nosy neighbors. The last thing you want is the people next door invading your private and personal religious space.
If you can’t devote that sort of space to your circle, don’t worry. Simply cast a smaller circle. The nine-foot Circle is not a prerequisite to effective magick. A smaller circle will work just as well. It really is a case of size doesn’t matter.
What does matter though, is where the boundaries are. It is a very good idea to get into the habit of marking them in some way. Candles, stones, flowers, or any combination of them will work well. Almost anything can be used.
The boundary should always be marked so that you do not inadvertently cross it and leave the circle when working within your sacred space. Having said that, it is possible to leave the circle during ritual and that will be covered shortly.