What Size Mattress Is In a Freightliner Cascadia? Dimensions, Fit, and FAQs

If you drive or are about to drive a Cascadia, it’s natural to ask: What size mattress is in a Freightliner Cascadia, and what do you need to know before replacing it? This guide walks through typical dimensions, variations between models, and how to choose a mattress that actually fits the sleeper berth.

What Size Mattress Is In a Freightliner Cascadia?

In many Freightliner Cascadia sleeper models, the standard lower bunk mattress is typically around:

• 38–40 inches wide
• 78–80 inches long

This is often referred to in the trucking world as a “narrow twin” or “truck twin” size. It’s similar in length to a regular twin, but usually slightly narrower to fit the cab’s layout.

Upper bunk mattresses, when present, are often narrower or shorter than the lower bunk. Exact dimensions can vary depending on:

• Model year (older vs. newer Cascadia)
• Sleeper configuration (mid-roof, raised roof, extended sleeper)
• Factory options and custom interiors

Because of this, the most reliable way to confirm what size mattress is in a Freightliner Cascadia is to measure your current bunk or platform.

How Do I Measure My Freightliner Cascadia Mattress Space?

Even if you already know what size mattress is in a Freightliner Cascadia generally, it’s important to confirm your own truck’s dimensions.

Step-by-step measuring tips:

1. Remove the existing mattress if possible.
2. Measure the inside length of the bunk platform, from head to foot.
3. Measure the inside width at the widest point.
4. Check for obstructions: curves, wall trims, fridge units, or cabinets that may cut into the usable space.
5. Note rounded corners or cut-outs; some truck mattresses are not perfect rectangles.

📝 Tip: Write down both the platform size and the current mattress size. The mattress may be slightly smaller than the platform to make it easier to fit and remove.

How Does Cascadia Mattress Size Compare to Standard Bed Sizes?

Many drivers wonder if they can use a regular household mattress. The answer is: sometimes, but often not perfectly.

Here is a simple comparison:

You’ll notice that the lower bunk is close to a Twin XL, but may require a slightly different length or width to avoid bunching or overhang at the sides.

Because truck bunks are built into a confined space, a mattress that’s even an inch or two too big can be hard to fit, especially when bedding is added.

Are All Freightliner Cascadia Mattresses the Same Size?

Not always. When people ask “What size mattress is in a Freightliner Cascadia?”, they often expect a single exact answer. In practice, there are some differences.

Common variations include:

• Different sleeper lengths: day cab vs. 48", 60", 72" sleepers, etc.
• Cab design updates between older and newer Cascadia generations.
• Optional upper bunks that use slimmer, shorter mattresses.

Because of these variables, treat general dimensions as a starting point, not a guarantee. Measuring your truck’s actual bunk space prevents ordering the wrong size.

What Should I Look For in a Replacement Mattress for a Cascadia?

Once you know what size mattress is in a Freightliner Cascadia (or at least the space it has to fit into), focus on a few key factors:

• Exact fit to the bunk

  • Look for a mattress that matches or is slightly smaller than your measured dimensions.
  • A snug but not overly tight fit is often easiest to manage in a compact sleeper.

• Thickness and headroom

  • A very thick mattress can reduce sitting or kneeling space in the bunk.
  • Many drivers prefer a medium profile height to balance comfort and maneuverability.

• Flexibility and weight

  • A lighter or more flexible mattress can be easier to lift, rotate, or remove for cleaning.

• Corner shape

  • If your bunk has rounded corners, a mattress with similar shaping or a slightly smaller rectangle can help bedding stay in place.

Can I Use Standard Sheets on a Cascadia Mattress?

Because the lower bunk is close to a Twin or Twin XL in size, many drivers use:

• Twin or Twin XL fitted sheets
• A flat sheet tucked tightly to accommodate minor differences in width or length

If your mattress is narrower than a standard twin, you may find:

• Fitted sheets are a bit loose on the sides
• Using sheet straps or carefully tucking the excess fabric improves the fit

Again, measuring your mattress first helps you choose bedding that works better for your setup.

✔️ Quick Mattress Takeaways

Key points consumers should understand about What Size Mattress Is In a Freightliner Cascadia:

• Most Freightliner Cascadia lower bunk mattresses are roughly 38–40" wide and 78–80" long, similar to a narrow Twin XL.
• Mattress sizes can vary by model year, sleeper configuration, and upper vs. lower bunk.
• The best way to know what size mattress is in a Freightliner Cascadia is to measure the bunk platform (length, width, and any corner shapes).
• Standard twin or Twin XL mattresses can sometimes work, but exact truck-specific sizes often fit better in the confined sleeper space.
• Pay attention to thickness, corner shape, and headroom when choosing a replacement mattress or bedding.

With accurate measurements and an understanding of typical Cascadia mattress dimensions, it becomes much easier to choose a mattress that fits your sleeper, supports your rest, and works with the space you have on the road.