What size is a semi truck mattress? Most semi truck mattress sizes are 80 inches long and 32 to 42 inches wide. Three sizes cover the majority of sleepers: 36 x 80, 38 x 80 and 42 x 80. Your exact size depends on make, model, sleeper length and bunk position.
Researched by Emeka Ogbonna, fifteen years OTR, owner operator. Last updated: September 2026.
Key Takeaways
- Length is nearly always 80 inches. Width runs from 32 to 42 inches. (SleepDog size guide)
- The Kenworth T680 stock mattress is 38 x 80 across trims, the same as a twin XL. (SleepDog)
- The Volvo VNL 860 ships with a 42 x 79 mattress, one inch shorter than the usual 80. (Rechtien International)
- The International LT 73 inch sleeper uses two different sizes: 42 x 80 lower and about 33 x 80 upper. (SleepDog)
- The biggest common factory berth is the Peterbilt Unibilt Ultra Sleeper at 51 x 75. (Raney’s Truck Parts)
- Federal rules set a floor of 75 x 24 inches for any berth installed after September 30, 1975. (49 CFR 393.76)
- Published charts disagree on the same truck by up to 6 inches of width. Measure before you order.
You are standing at the fuel desk with your phone, and your mattress has a trench where your hips go. You want a new one. The first question is size, and the internet gives you five answers for the same truck.
This page puts every published size in one chart, shows where the sources disagree, and tells you how to measure so the one you order actually fits.
What size is a semi truck mattress?
There is no single standard semi truck mattress size. Almost every sleeper takes an 80 inch long mattress, and the width is what changes. Widths run from 32 inches on upper bunks to 42 inches on big lower bunks.
Mattress makers have settled on a few repeat sizes. SleepDog, which makes truck specific mattresses, sells four: Size A at 36 x 80, Size B at 39 x 80, Size C at 42 x 80 and Size D at 32 x 80. Raney’s Truck Parts says its best sellers range from 38 x 80 to 42 x 80.
Key semi truck mattress size numbers. Sources: SleepDog, Raney’s Truck Parts, Rechtien International, 49 CFR 393.76.
What mattress size fits my truck? The full chart by make and model
Find your make and sleeper below. Where two sources list different sizes for the same truck, both are shown with the source. Treat every number here as a starting point, not a guarantee. Fleets and dealers spec trucks differently, and model years change the berth.
| Make | Model and sleeper | Mattress size (inches) | Source |
|---|---|---|---|
| Freightliner | Cascadia, factory mattress (most frequent) | 36 x 80 | SleepDog |
| Freightliner | Cascadia, other configurations | 39 x 80 or 42 x 80 | SleepDog |
| Freightliner | Condo couch | 42 x 80 | Raney’s |
| Freightliner | Century Class | 39 x 80 (38 x 80 twin XL may fit) | SleepDog |
| Freightliner | Columbia | 32 x 80 or 36 x 80 | SleepDog |
| Freightliner | Coronado | 32 x 80 (most configurations) | SleepDog |
| Kenworth | T680 (all trims, per SleepDog) | 38 x 80 | SleepDog, Raney’s |
| Kenworth | T680 52 in mid roof, lower bunk | 32 wide standard, 38 wide optional | Kenworth |
| Kenworth | T680 52 in mid roof, upper bunk | 28 wide | Kenworth |
| Kenworth | T680 bunk configuration | 32 x 80 | SleepDog |
| Kenworth | W900, W990 sleepers | 42 x 80 | SleepDog |
| Kenworth | T2000 | 38 x 80 | Raney’s |
| Peterbilt | 579 | 36 x 80 or 42 x 80 | SleepDog |
| Peterbilt | 389, 379 | 36, 38 or 42 x 80 by sleeper | Fleetsworld |
| Peterbilt | 567 80 in sleeper | 42 x 80 | SleepDog |
| Peterbilt | 36 or 48 in Unibilt sleeper | 32 x 70 | Raney’s |
| Peterbilt | 63 in Unibilt sleeper | 38 x 80 | Raney’s |
| Peterbilt | 70 in Unibilt sleeper | 42 x 80 | Raney’s |
| Peterbilt | Unibilt Ultra Sleeper | 51 x 75 | Raney’s, Rechtien |
| Peterbilt | 397, 587 mid roof | 32 x 79 or 32 x 80 | Rechtien, Raney’s |
| Peterbilt | 397, 587 high roof | 42 x 80 | Rechtien |
| Volvo | VNL 860 | 42 x 79 | SleepDog, Rechtien |
| Volvo | VNL 760, 740 | 39 x 80 (sleep space 39 x 81) | SleepDog |
| Volvo | VNL 730, 770, 780 | 38 x 80 | Raney’s |
| Volvo | VNL 430, 630, 670 | 36 x 80 | Raney’s |
| Volvo | 880 | 42 x 80 or 36 x 76 | Raney’s |
| Volvo | 610 | 36 x 76 | Raney’s |
| International | LT 56 in sleeper (low roof or hi rise) | 36 x 80 | SleepDog |
| International | LT 73 in sleeper, lower | 42 x 80 | SleepDog, Rechtien |
| International | LT 73 in sleeper, upper | 33 x 80 (Rechtien lists 33.2) | SleepDog, Rechtien |
| International | ProStar, LoneStar 73 in lower | 42 x 80 | Raney’s, Rechtien |
| International | ProStar 56 in sleeper | 36 x 80 | SleepDog, Rechtien |
| International | 9900i 51 in sleeper | 36 x 80 | Raney’s, Rechtien |
| International | 9900i 72 in sleeper | 42 x 80 (Rechtien lists 36 x 80 for the 72 in Hi Rise) | Raney’s, Rechtien |
| International | 9900i Sky Rise, lower and upper | 37 x 80 lower, 30 x 86 upper | Rechtien |
| Mack | Anthem 48 in or 70 in sleeper | 32 x 80 or 36 x 80 | SleepDog |
| Mack | Pinnacle | 38 x 80 (SleepDog also lists 36 x 80) | Raney’s, SleepDog |
| Western Star | 4900, 4700 | 42 x 80, 38 x 80, 36 x 78 or 35 x 79 | Absolute Mattress |
| Western Star | 57X (60 in mid roof, 72 in high roof) | 36, 38 or 42 x 80 | SleepDog |
Semi truck mattress size chart compiled September 2026 from manufacturer, dealer and mattress maker sources. Sizes are width x length in inches.
Freightliner
The Cascadia is the truck where sources fight the most. SleepDog says the factory mattress is most often 36 x 80, and that some Cascadias take 39 x 80 or 42 x 80. Other sellers print 42 x 80 as “the” Cascadia size. The Cascadia sleeper comes in lengths from 48 to 72 inches in mid roof and raised roof, so both can be right on different trucks.
Kenworth
SleepDog says the T680 stock mattress is 38 x 80 on every trim, and Raney’s lists the same size. Kenworth’s own announcement for the T680 52 inch mid roof sleeper gives a 32 inch lower bunk standard, a 38 inch lower option and a 28 inch upper. So a regional T680 can take a much narrower mattress than a long haul one. The W900 and W990 sleepers take 42 x 80.
Peterbilt
Peterbilt has the widest spread of any make. The small 36 and 48 inch Unibilt sleepers take a 32 x 70, which is 10 inches shorter than almost everything else on this page. The Unibilt Ultra Sleeper takes a 51 x 75, the widest berth in any chart I found. The 579 usually takes 36 x 80 or 42 x 80. If you run a Pete, the sleeper length matters more than the model number.
Volvo
Watch the length on a VNL 860. SleepDog says the factory mattress is 42 x 79, and Rechtien lists the same. An 80 inch mattress may bunch at one end. The older VNL 730 to 780 range takes 38 x 80. Volvo’s second generation VNL, built from October 2024, comes in 42, 64 and 74 inch sleeper lengths, and no mattress maker has published a verified size for it yet. Measure that one.
International
The LT and ProStar 73 inch sleepers use two sizes in one truck: 42 x 80 on the bottom and about 33 x 80 on top. Order the wrong bunk and it will not fit. The 56 inch sleepers take 36 x 80. On the 9900i, Raney’s and Rechtien disagree on the 72 inch sleeper, so measure before you order.
Mack and Western Star
SleepDog says 32 x 80 and 36 x 80 commonly work in an Anthem. The Pinnacle is listed at 38 x 80. Western Star is the thinnest data on this page. Older 4900 and 4700 sleepers run anywhere from 35 x 79 to 42 x 80, and SleepDog lists three possible widths for the current 57X. Measure a Western Star every time.
Why do sources disagree on the same truck’s mattress size?
They disagree because one model name covers many sleepers. A Cascadia can be a 48 inch mid roof or a 72 inch raised roof. A T680 runs from a 40 inch flat top to a 76 inch high roof. Each has its own berth.
Three more things move the number:
- Upper vs lower bunk. The LT 73 inch sleeper is 42 inches wide on the bottom and about 33 on top.
- Factory mattress vs berth. Some charts list the stock mattress. Others list the platform. The VNL 760 sleep space is 39 x 81, but the mattress that fits is 39 x 80.
- Seller bias. A retailer that stocks mostly 42 x 80 mattresses has a reason to call 42 x 80 the answer. That is why this chart shows the source on every row.
The honest answer for most trucks is a range. Your tape measure turns the range into one number.
What do Size A, B, C and D mean on a truck mattress?
Those are SleepDog’s labels, and other sellers now copy them. They are not an industry standard, but they are handy shorthand when you shop.
| Size | Dimensions (inches) | Where it shows up |
|---|---|---|
| Size D (bunk) | 32 x 80 | Upper bunks, T680 bunk setups, Peterbilt 397 mid roof, Mack Anthem |
| Size A | 36 x 80 | Cascadia factory, Peterbilt 579, International LT and ProStar 56 in |
| Twin XL | 38 x 80 | Kenworth T680, Volvo VNL 730 to 780, Mack Pinnacle, Peterbilt 63 in Unibilt |
| Size B | 39 x 80 | Some Cascadias, Volvo VNL 740 and 760, Freightliner Century Class |
| Size C | 42 x 80 | LT 73 in lower, W900, W990, Peterbilt 70 in, VNL 860 (42 x 79) |
| Ultra Sleeper | 51 x 75 | Peterbilt Unibilt Ultra Sleeper, widest common factory berth |
SleepDog’s own page notes that Size A is 2 inches narrower than a twin XL and Size B is 1 inch wider. Those 1 and 2 inch gaps are exactly why a household twin XL fits some trucks and slides around in others.
How thick can a semi truck mattress be?
Thickness is limited by headroom, not by the berth. SleepDog recommends anywhere from 2 to 10 inches and sells a 7 inch and a 9 inch. Raney’s best sellers are 6.5 and 10 inches.
The floor is set by federal rule. A foam berth mattress must be at least 4 inches thick, and a berth built after 1975 needs 24 inches of clear height above the top of the mattress. That second number is the one that stops a thick mattress under an upper bunk.
Here is the check: measure from the platform to the lowest thing above it. Subtract the mattress thickness. If what is left is tight, you will be crawling in sideways every night.
How do you measure your sleeper berth before buying a semi truck mattress?
Take the old mattress out and measure the platform, not the old mattress. A worn mattress has shrunk, bulged or been cut down by the last driver.
- Width in three places. Head, middle and foot. Raney’s notes berths are not always exactly rectangular, so a mattress can fit one end and jam at the other. Use the smallest width.
- Length on both sides. Wall side and aisle side. Use the shorter one.
- Corners. Rounded corners and cabinet edges eat into the mattress. Note the radius if one is tight.
- Height clearance. Platform to the lowest thing above it. This sets your maximum thickness.
- Lift or fold. If your bunk lifts for storage or folds up, check the hinge side for clearance with the thicker mattress on it.
- Write it down with the truck. Year, make, model, sleeper length and which bunk. You will need it again for sheets.
Can a regular twin or twin XL mattress fit a semi truck?
A twin XL fits some trucks and not others. A twin XL is 38 x 80, which matches the stock size in the Kenworth T680, Volvo VNL 730 to 780 and Mack Pinnacle. In a 36 inch Cascadia berth it is 2 inches too wide. In a 42 inch berth it leaves a 4 inch gap where your stuff falls down.
A regular twin is 75 inches long, 5 inches short of most berths. The main difference between a truck mattress and a home mattress is just the dimensions, according to SleepDog. So if a household size matches your berth, it will work.
What should you do once you know your semi truck mattress size?
Once you know your size, the next step is picking the mattress itself. I will cover that in a road tested roundup once I have slept on the contenders long enough to say something honest. Until then, the rest of the mattresses and fitment guides and the cab comfort guides are on the blog, including what the research says about seat cushions for drivers.
Drivers who want to send in their own bunk measurements can reach me through the contact page. Every measurement that comes in makes this chart better. You can read more about who writes this site on the About page and in the FAQ.
Frequently Asked Questions
What is the most common semi truck mattress size? The three sizes you will see most are 36 x 80, 38 x 80 and 42 x 80 inches. Length is almost always 80 inches. Width is what changes from truck to truck.
Is a semi truck mattress the same as a twin XL? The length matches. A twin XL is 38 x 80 inches, the same as the stock mattress in many Kenworth T680 and Volvo VNL 730 to 780 sleepers. Most other sleepers are narrower or wider than 38 inches, so a twin XL will not fit everywhere.
What size mattress fits a Freightliner Cascadia? Depending on year and sleeper, the Cascadia takes a 36 x 80, 39 x 80 or 42 x 80 mattress. SleepDog lists 36 x 80 as the most frequent factory size. Measure your own berth before ordering.
What size mattress fits a Kenworth T680? SleepDog and Raney’s both list 38 x 80 as the stock T680 size. Kenworth’s own spec for the 52 inch sleeper is a 32 inch wide lower mattress standard, with a 38 inch option and a 28 inch upper bunk.
What size mattress fits a Volvo VNL 860? The VNL 860 comes with a 42 x 79 inch factory mattress according to SleepDog and Rechtien International. That one inch short of 80 matters when you order.
How thick should a semi truck mattress be? SleepDog recommends 2 to 10 inches, and most replacements sold run 6.5 to 10. Federal rules require a foam berth mattress to be at least 4 inches thick. The real limit is headroom under your upper bunk or cabinets, so measure that before you buy a thicker mattress.
What is the biggest mattress that fits in a semi truck? Among common sleepers, the Peterbilt Unibilt Ultra Sleeper has the largest listed berth at 51 x 75 inches. Custom sleepers can be bigger, but that is the biggest factory size in the published charts.
How do I measure my sleeper berth for a new mattress? Take the old mattress out. Measure the platform width at the head, middle and foot, and the length along both sides. Use the smallest numbers. Then measure the height from the platform to the lowest thing above it, like the upper bunk or a cabinet, to find the thickest mattress you can run.
Methodology and Sources
This chart combines 39 make and model rows from 8 published sources, checked in September 2026: SleepDog Mattress (size guide and 8 model pages), Raney’s Truck Parts, Rechtien International Trucks, Kenworth’s T680 sleeper announcement, Fleetsworld, Absolute Mattress, Wikipedia’s Freightliner Cascadia and Volvo VN entries, and the federal sleeper berth rule at 49 CFR 393.76. Where sources disagreed, both figures are shown with the source. Everything in this chart is Researched: these are published figures, not measurements from my own truck. A search of driver forums for measured sizes returned only retail listings, so no forum figures are used. Sizes change with model year and dealer spec. Always measure your own berth.
- SleepDog Mattress. “Semi Truck Mattress Size Guide and Dimensions.” sleepdogmattress.com
- Raney’s Truck Parts. “Picking the Right Size Mattress for Your Semi Truck.” raneystruckparts.com
- Rechtien International Trucks. “Semi Truck Mattress Size.” rechtien.com
- Kenworth. “T680 52 inch Mid Roof Sleeper Available with Optional Upper Bunk.” kenworth.com
- Fleetsworld. “What Size is a Semi Truck Mattress?” fleetsworld.com
- Absolute Mattress. “How To Size A Replacement Semi Truck Mattress.” absolutemattress.com
- Electronic Code of Federal Regulations. “49 CFR 393.76 Sleeper berths.” ecfr.gov
- Wikipedia. “Freightliner Cascadia” and “Volvo VN.” Cascadia, Volvo VN
Emeka Ogbonna has driven over the road for fifteen years, across several carriers, and now runs his own truck. Everything on this site is either tested in that truck or clearly labeled as researched.
Contributing writer at Sleeper Cab Gear.