How to Calculate the Volume of a Truck Trailer

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If you are in a manufacturing or warehousing industry, the chances are that you ship goods by the truckload on a regular basis. Even a shipment that is carried by ship or train probably begins and ends the journey pulled by a truck. Each time a "big rig" truck with a trailer pulls out on the road, it costs money to operate the vehicle and pay the driver.

These realities mean that maximizing the use of the space available in a trailer is critical to effectively controlling shipping costs. The goal is to fit as much as possible into each trailer that leaves your facility. The first step in proper truck load management is determining the volume in a truck trailer.

Truck Trailer Measurements, Volume and Weight

Truck trailers come in many sizes ranging from 10 or 20 feet to more than 50 feet in length, and with varying heights. Some are shipping containers that are transported by rail or ship, but that can be mounted on a chassis and function as part of a tractor-trailer rig. Other trailers are designed exclusively as over-the-road trailers.

Measuring trailer volume is not always necessary. For example, flatbed trailers are open platforms, so there is no specific volume limit. For conventional or "dry" trailers, the volume is more important than weight most of the time. Of course, if you need to ship a load of bricks to a construction site, the weight matters because you will reach the truck's load limit long before you fill the trailer. However, most goods are not dense enough to exceed the weight limit even when a trailer is packed floor to roof. Trailer volume is the limiting parameter with such loads.

Truck Measurement Calculation

The formula for a truck measurement calculation is straightforward: height times width times length. You'll only need a tape measure, a stepladder for the height measurement and a calculator. Make your measurements on the interior of the trailer, not the exterior. You will need to convert your measurements to decimal form to enter them into the calculator. For example, 8 feet 2 inches becomes 8.17 feet and 8 feet 6 inches is 8.5 feet.

Measure and record the height and do the same for the width. For example, you might find that the trailer is 8 feet 2 inches on the inside or 8.17 feet. You measure the height at 8 feet 6 inches or 8.5 feet. When you measure the length of the trailer, close one trailer door and measure from the inside of the door. If you measure the floor of the trailer with the doors open, you may include several inches that will be taken up by the door and latching mechanism when you close up the trailer. Suppose you get 48 feet for the trailer length.

Multiply the figures together to calculate the trailer volume. You have 8.17 feet times 8.5 feet times 48 feet. This gives you a truck trailer volume of 3332 cubic feet.

Load Scan Technology

If your shipping volume is sufficient to justify the investment, you may want to consider load scan technology. A load scanning system automates the process of calculating load volumes. The procedure is simple. Drive the trailer under the load scanner and it will measure the volume of the trailer and the load inside, and also create a 3-D profile of the load. This eliminates the time-consuming process of manually measuring truck trailers. It's also a useful training tool. You can use the 3-D profile to show loaders how to correct problems and load truck trailers more efficiently so that you get the maximum use of the available trailer space.