Quick answer: Most semi truck mattresses come in one of three sizes: 42x80 (the most common, used in most Peterbilt, Kenworth and Mack Anthem sleepers), 39x80 (most Freightliner Cascadia sleepers) and 36x80 (narrower and older bunks). Sleeper configurations vary by model, year and sleeper length, so always measure your bunk platform, not your old mattress, before you order. If your bunk doesn't match a standard size, a custom mattress is built to your exact measurements.
Ordering the wrong size is the most common mistake drivers make when they replace a sleeper mattress. Too wide and it bows up against the walls. Too narrow and you get a gap that eats your pillow and lets the mattress slide. Here's how to get it right the first time.
The 3 standard semi truck mattress sizes
| Size | Width x length | Commonly fits |
|---|---|---|
| 42x80 | 42" x 80" | Most Peterbilt 579 and 389, Kenworth T680 and Mack Anthem sleepers |
| 39x80 | 39" x 80" | Most Freightliner Cascadia and Classic XL sleepers |
| 36x80 | 36" x 80" | Narrower and older sleeper bunks |
All three are 80 inches long, which is about 5 inches longer than a standard twin. That extra length matters when you're stretched out after an 11-hour day.
Is a truck mattress the same as a twin or twin XL?
No. A twin is 38x75 and a twin XL is 38x80. A twin XL is close to a 39x80 truck mattress, but it's an inch narrower, and in a 42-inch bunk it leaves a 4-inch gap. Household mattresses also aren't built to the same flammability standard as truck sleeper mattresses, so a purpose-built truck mattress is the safer choice.
Mattress size by truck make
These are the most common sizes, not guarantees. Sleeper length, model year and factory options all change the bunk, so treat this as a starting point and measure to confirm.
- Freightliner Cascadia: usually 39x80. A 42x80 usually won't fit. See our Freightliner mattress guide.
- Peterbilt 579 and 389: usually 42x80. See Peterbilt truck mattresses.
- Kenworth T680: usually 42x80. See Kenworth truck mattresses.
- Mack Anthem: usually 42x80. Mack Pinnacle and Granite bunks often don't match a standard size, so plan on measuring for custom. See Mack truck mattresses.
- Volvo VNL: varies by model and sleeper length. Measure first. See Volvo truck mattresses.
- International LT: varies by sleeper configuration. Measure first. See International truck mattresses.
How to measure your sleeper bunk
Measuring takes about five minutes, and it's the difference between a mattress that fits and one that goes back on a truck.
- Take the old mattress out. Measure the bunk platform itself. Old mattresses compress and sag, so they're not a reliable guide.
- Measure the width edge to edge across the platform, at the head, middle and foot. Use the smallest number.
- Measure the length from wall to wall along the platform.
- Note the corners. Are they square, rounded, angled or notched around a cabinet or seatbelt mount? Rounded and angled corners usually mean custom.
- Check the height clearance between the platform and anything above it, like an upper bunk or cabinet, so a thicker mattress still leaves room to sit up.
- Round down, not up. If you measure 41.5 inches, a 42x80 will be tight. Go with what fits the smallest measurement.
What if my bunk isn't a standard size?
That's common with Mack Pinnacle and Granite sleepers, older trucks and aftermarket sleepers. Forcing a standard mattress into a non-standard bunk leaves gaps or makes the mattress buckle. A custom semi truck mattress is built to your exact width, length and corner shape, using the same 12-inch hybrid construction as the standard models.
Does mattress thickness matter in a truck?
Yes. Factory sleeper mattresses are often just a few inches of foam, which is why so many drivers wake up with sore hips and a stiff back. A 12-inch hybrid with individually encased coils spreads your weight and supports your spine. Just confirm you'll still have head clearance if your truck has an upper bunk or low cabinets. For more on how a thin mattress affects your back, see truck driver back pain.
SleeperKing mattresses in every standard size
Every SleeperKing semi truck mattress is a 12-inch hybrid made in the USA with Spring Air components, available in 36x80, 39x80 and 42x80, with free shipping. They ship roll-packed so they fit through the cab door.
- Classic: 850 individually encased coils and a dual steel seating edge. The best value.
- Serenity: 1,000 comfort coils with a copper-infused lumbar layer for lower back support.
- Premium: double-sided, with a cool gel side and a warming side, 1,000 coils and three-zone support.
Not sure which one fits how you sleep? Read our best semi truck mattress comparison.
Frequently asked questions
What size mattress is in a semi truck?
Most semi truck sleepers take a 42x80, 39x80 or 36x80 mattress. 42x80 is the most common, found in most Peterbilt, Kenworth and Mack Anthem sleepers. Measure your bunk platform to confirm.
What is the most common semi truck mattress size?
42x80 is the most common semi truck mattress size. Freightliner Cascadia sleepers are the main exception and usually take 39x80.
Will a twin XL mattress fit in a semi truck?
A twin XL is 38x80, so it's an inch narrower than a 39x80 bunk and four inches narrower than a 42x80 bunk. It will leave a gap, and household mattresses aren't built to the same flammability standard as truck sleeper mattresses.
How do I measure my semi truck bunk for a mattress?
Remove the old mattress and measure the bunk platform edge to edge in width and length. Measure the width in three spots and use the smallest number, and note any rounded or angled corners.
What if my sleeper bunk is not a standard size?
Order a custom mattress built to your exact width, length and corner shape. This is common with Mack Pinnacle, Mack Granite, older trucks and aftermarket sleepers.
