To determine the best overall dimensions for your intended use, there are several things to keep in mind. Sticking with the example of a two-car garage, are the cars compact cars or full size trucks? A good estimate for depth is 14 feet for an average car, 18 feet for a small truck or SUV and 20 feet for a full-size truck plus space for storage. A typical car is 6 feet wide. Providing enough room to open the doors on either side of the car requires the garage to be a minimum of 12 feet wide. For a small or full-size truck, the suggested width is 14 feet. If a two-car garage is planned, simply double the widths above for a good suggested width.
Another point to consider is the width and height of the door (or doors) on the garage. For a single door on a two-car garage, the options are usually 16 feet or 18 feet. If you are using two doors, 8 feet wide by 6 feet 8 inches high are sufficient for the average car. However, for trucks, or simply for extra room, a 9-feet wide by 7-feet high door is recommended.
When planning your garage, there are many other things to consider such as the amount of storage space desired, ceiling height and attic access.
