The best size for a hitting mat depends on your personal needs and the space available for the mat. However, most hitting mats for golf or baseball are around 5 feet by 5 feet or 5 feet by 7 feet. These sizes provide enough space to comfortably swing and hit a ball without worrying about stepping off the mat or damaging your surroundings.
If you plan to use the mat primarily for indoor practice, you may want to consider a smaller size such as 3 feet by 5 feet or 4 feet by 4 feet. This will allow you to practice your swing and ball contact without taking up too much space in your home.
On the other hand, if you have a larger outdoor space and want to practice a wider range of shots, a larger mat such as 5 feet by 10 feet or 6 feet by 12 feet may be more appropriate. These sizes can accommodate full swings with longer clubs and allow you to practice hitting off different lies and angles.
Ultimately, the best size for a hitting mat will depend on your personal preferences, the types of shots you want to practice, and the space available for the mat.