In general cargo trailers are simply boxes with wheels and hitches. The boxes come from 4 ft. wide to just over 8 ft. wide. Most manufactures measure their trailer from the outside walls. For ex. a 5x8 trailers interior width is about 4ft. 8 inches. In most cases the length is also minus the walls. When it comes to interior ht. 4ft wide trailers are actually a full 4 ft tall inside, 5 ft. wide a full 5 ft. tall, 6 ft. wide a full 6 ft. tall. Standard heights for 7 wide are only 6 ft tall in general. Most trailers can be ordered with height added or subtracted for an extra charge and are sometimes available in stock.
The three major things to keep in mind when choosing the proper trailer is the 1. volume of the unit 2. total of the weight capacity of the trailer and the empty wt. of the trailer (GVWR) 3. towing capacity of your vehicle.
