The SleepDog® mattress is our 7” low profile dual layer memory foam mattress with a medium-firm feel that contours to your body and minimizes motion transfer to accommodate semi-truck or RV traveling.
Shop NowSize B, 39" x 80" Semi Truck Mattresses
A relatively common truck mattress size, the size B semi truck mattress measures 39” wide by 80” long, meaning it measures 1” wider than a standard twin or twin XL mattress.
How big is a size B semi-truck mattress?
Measuring 39” wide by 80” long, a SleepDog® Size B truck mattress comes in at 1” wider than a standard twin or twin XL and maintains the same length as standard twin XL, queen, and king mattress sizes.
What semi-truck models fit a size B truck mattress?
Freightliner Cascadia
Cascadia models are often equipped with 36” x 80” mattresses along with other customizable amenities.
Volvo VNL 760 & 740
An airline inspired sleep cabin experience, the Size B SleepDog® brings even more comfort to the Volvo sleep setup.
*Please note: When looking for a replacement mattress it is important to know the exact measurements of your sleeping area. While most sleeper cabins accommodate standard semi-truck mattress sizes, the best and most accurate way to measure for your new mattress is to measure the width and length of your sleeper berth.
120-night risk-free trial
Try your size B semi-truck mattress risk-free for 120 nights. If you don't love your new SleepDog® truck mattress after sleeping on it for 60 nights, let us know and we will get the return process started. Details can be found in our Return Policy.
Built for the road
All of the memory foam we develop for our truck and RV mattresses is CertiPUR-US® certified and DOT approved. This means that the foam in each semi truck mattress has been tested by accredited labs and has been certified as safe to sleep on, as well as appropriate for road travel. We use multiple layers of our house-made memory foam to provide the perfect balance of support and pressure relief for all sleepers.
Sleep now, pay later
We partner with Affirm to offer flexible financing options, so you can pay with fixed monthly payments with rates between 0-30% APR. Simply select Affirm at checkout and complete an application that won’t affect your credit score. Prequalify Now.
Which B Size SleepDog® is right for you?
The BigDawg® features a 9” plush multilayer memory foam and quilted foam cover construction, making it a double-sided mattress that can be flipped for either a soft or firm feel.
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Frequently Asked Questions
What measurements does a Size B semi-truck mattress have?
Size B semi-truck mattresses come in at 1 inch wider than standard twin size mattresses, measuring 39 inches wide by 80 inches long. Their 80 inch length measures the same as standard twin XL, queen, and king size mattresses.
Which semi-trucks can accommodate a Size B truck mattress?
Truck sleeper cabins in semi truck models including the Freightliner Cascadia and the Volvo VNL 760 & 740 are frequently equipped with Size B, 39” x 80” mattresses.
What makes SleepDog® Size B truck mattresses suitable for over-the-road use?
Size B SleepDog® mattresses are DOT approved and designed with multiple layers of CertiPUR-US® certified memory foam to give truck drivers a safe and supportive place to sleep. The mattresses are built to minimize motion transfer and provide pressure relief for all body types while withstanding the rigors of road travel.
Is there a trial period for SleepDog® Size B truck mattresses?
Yes. SleepDog® provides a risk-free 120-night sleep trial for all truck mattresses and RV mattresses. If you’re not satisfied with your Size B truck mattress after sleeping on it for 60 nights, you may begin the return process. See the Return Policy for further information.
What is the difference in firmness between the SleepDog® and BigDawg® mattress?
The Size B SleepDog® truck mattress maintains a medium-firm feel with it’s 7” multilayer memory foam construction. The Size B BigDawg® truck mattress is a double-sided mattress that offers both a soft side topped with a quilted foam cover or a firmer side.