How tall inside semi trailer?

The typical maximum interior height of a semi-trailer in the United States is 13 feet 6 inches (4.11 meters). This height is regulated by the Federal Motor Carrier Safety Administration (FMCSA) and is considered the maximum allowable height for safe operation on public roads. However, some semi-trailers may have slightly lower interior heights due to various design factors or to meet specific requirements for certain types of cargo. It's important to note that the exact interior height of a particular semi-trailer can vary depending on the specific make, model, and purpose of the trailer.