How long is a semi-truck? And other 18-wheeler dimension facts

Estimated reading time: 3 minutes

Semi-trucks are responsible for moving most of the country’s freight, making them an essential part of the supply chain and everyday living. While most people see semi-trucks all over the nation’s highways, few take the time to consider or appreciate just how large the vehicles are.

Here, we won’t only answer “how long is a semi-truck?” but break down everything else you need to know about semi-truck dimensions.

How long is a semi-truck?

Combining the tractor and trailer, a standard semi-truck's length is about 70 feet long.

The length can vary considerably, though, based on a variety of factors.

1. Type of tractor.

Day cabs are typically 20 feet long, though each manufacturer and spec can alter that. Sleeper cabs, which have a bed inside for drivers who haul over-the-road, are also around 20 feet in length.

2. Type of trailer.

• A standard dry van trailer is 53 feet long. It overlaps a few feet over top of the tractor, making the unit about 70 feet.
• Pup trailers are typically 28 feet in length. It is common to see two pup trailers pulled together, making for a total length of around 56 feet.
• Intermodal containers are typically 20 or 40 feet long but can also reach the standard 53 feet.
• Tanker trailers, flatbeds and a variety of other trailer types all range between 48-53 feet.
• Extendable double drops and Removable Goosenecks (RGN) are some of the longest trailers available. Both reach 80 feet long when fully extended and typically carry other vehicles and large equipment.

3. State requirements.

Companies can often get creative with the length of their equipment for specialty freight needs, but each state has different regulations for overall length.

While Texas and Oklahoma allow trailers to be 59 feet long, most states cap trailer length at 53 feet.

How tall is a semi-truck?

A standard semi-truck's height is about 13 ½ feet tall.

The height of a semi-truck depends on various factors.

1. Type of tractor.

Most tractors, sleeper or day, reach 13 ½ feet tall when including the height of the wind fairing. Cabs themselves range anywhere from 6-10 feet tall depending on their make and model.

2. Type of trailer.

• Standard dry van trailers are typically 13 ½ feet tall in total, with the door height making up 9 feet of that.
• Flatbed trailers are typically only 5 feet tall, but can hold cargo around 8 ½ feet tall.
• Intermodal trailers are typically 9 ½ feet tall, as they must adhere to standards for railways as well as roads.
• Less standard trailers, like step decks and double drops, go as low as 3 ½ feet and 1 ½ feet tall, respectively.