Generally, a two-car garage should measure at least 18 feet by 20 feet. Customers may need a little larger garage depending upon the size of the vehicles they intend to store.
American Garage Builders has a useful diagram on its website that may help consumers select the size of a two-car garage based on the sorts of vehicles they intend to store. They can go to the site and choose the image that would best fit their needs. The need for an extra half size may become necessary for storing trucks and larger motor vehicle or if the garage must also accommodate recreational vehicles, such as boats or motorcycles.