How To Size A Replacement Semi Truck Mattress

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Over the road truck drivers spend a lot of time away from home. Having the right semi truck mattress in your cabin can make the difference between a good night’s sleep and a lousy one. A replacement sleeper cab mattress that fits your space, supports your body, and keeps you comfortable is an amenity that’s worth the investment for long-haul truckers. When you need a mattress for a sleeper cab, where do you start? 

The most common question people ask when looking for a replacement semi truck mattress is, what size fits in my sleeper cabin? This handy guide—and a measuring tape—will point you in the right direction.  

Sleeper Mattresses vs. Residential Mattresses

Semi truck mattresses don’t come in standard sizes like the ones in a mattress store. Semi truck manufacturers design their cabs with sleeping berths that vary in length, width, and height. If you know the make and model of your truck, finding the right mattress size should be pretty easy. That said, there is one mattress size that nearly half of all semi truck manufacturers offer. 

Semi truck sleeper

The Most Common Semi Truck Mattress Size: 42×80

By far the most common truck mattress size in the U.S. is 42” wide by 80” long. Three of the top American brands—Freightliner trucks, International trucks, and Kenworth trucks—make sleeper cabs that fit a 42×80-inch mattress. It’s the most common size for a bottom berth in a semi truck, and that’s why you’ll find it listed more than others when you do an Internet search.

Other, less common sizes you can find are 40×80, 38×80, 32×79, 36×76, and 35×79 inches. It helps to know which truck models fit these sizes. 

Sleeper Cab Mattress Sizes By Truck Brand

Let’s take a look at the semi trucks commonly found on American highways, and some of the common mattress sizes they take. The following information should give you a ballpark of your mattress size. 

Freightliner Trucks

The Cascadia and the 122SD are on-highway Freightliner trucks with sleeper cabs. The newest Cascadia model fits a 40×80 inch mattress, but other common Freightlner mattress sizes are 42×80, 39×80, 38×80, and 34×80. 

International Trucks

The LT Series, LoneStar, RH Series, and Prostar from International Trucks are semi truck models with sleeper cabs. Two common semi truck mattress sizes they offer are 42×80 and 36×79. 

Kenworth Truck Company

Kenworth’s most popular sleeper semis are the W990, W900, and T680. These Kenworth trucks tend to have mattresses that are 42×80, 42×78, 38×80, or 32×80. 

Peterbilt Motor Company

The most common sleeper models for Peterbilt trucks are the 579 and 389, and these are the mattress sizes that fit in the berths, depending on the configuration: 42×78, 36×85, and 35.5×78.

Mack Trucks

Mack makes the Anthem and Pinnacle with sleeper cabs. The two most common semi truck mattresses for those Mack trucks measure 38×80 and 36×75.  

Western Star Trucks

The Western Star 4900 and 4700 models feature sleeper cabs with mattresses in the following sizes: 42×80, 38×80, 36×78, and 35×79. 

Volvo Trucks

The VNL series of Volvo trucks matches the following four semi truck models with these specific mattress sizes: 

  • VNL400 36×75
  • VNL 740 39×81
  • VNL 760 39×81
  • VNL 860 42×79

Does Thickness Matter for Semi Truck Mattresses?

When looking for a semi truck mattress for your sleeper cab, the most important dimensions to consider are width and length. Mattress thickness does not matter that much, because a well constructed truck mattress should be plush and supportive without a lot of bulk.

Be aware that mattresses made from layers of memory foam and other supportive materials, such as inner springs, can add height. It’s always a good idea to ask about the height of a replacement mattress and not just the length and width. Remember, you probably don’t have a lot of head room, so a thick mattress will just take up valuable space. 

The Wrong Size Truck Mattress Can Be a Hazard 

Don’t underestimate the importance of getting the right mattress size for a truck berth. A mattress that’s too small can slide around, causing injury.

A mattress that is too large for a berth won’t lay flat and provide the proper support and comfort. It may ride up on one or more ends of your berth, or hang over, taking up too much room and leaving you unsupported.

If you have back issues or muscular pain, you’ll definitely want to make sure your mattress fits flat and snugly in your cab. Your mattress needs to help you sleep better, not worse!

Measuring a semi truck mattress

Two More Tips for Truck Mattress Sizing

Grab a Tape Measure

Probably the best way to ensure you have the right sized mattress for your sleeper cab is to measure the space you want to fill. Crawl into your bunk space and measure the length, width, and height. Measure to the nearest quarter inch. Then select a mattress that matches the length and width measurements as closely as possible, knowing that you don’t want to round up on the actual mattress size, or it will be too big. 

Check the Label on Your Mattress

If the old mattress in your sleeper cab fits well, then take a look at the law label sewn into the side of the mattress. This label is required to lists the materials used to make your mattress, and, more importantly, it also gives you the finished size. 

What is a Law Label?

The label on your mattress that says “Do not remove this tag under penalty of law” is there to protect consumers.