RV Bunk Mattress Sizes and Corner Cuts Explained
Most straight RV bunk mattress sizes are about 75 inches long and 28, 30 or 34 inches wide. Corner-cut bunks need a measured cut, so measure the angled edge before you order.
On this page (6 sections)
Bunk size matters more than in any other RV bed, because bunks sit in tight frames with rails, ladders and sometimes cut corners. A mattress even 1 inch too wide can bow up against the wall or keep a rail from sitting flush.
Bunks come in more shapes than beds, so a size name only tells part of the story. Use the table to find the closest common size, then measure your own bunk before you order.
Our RV mattress sizes guide covers every common RV bed, from short queens and kings to bunks. If you're sizing the main bed instead, see short queen mattress dimensions.
What RV bunk mattress size fits your bunk?
Most straight RV bunks take one of the widths in the table, and most run about 75 inches long. Double bunks are wider, so they need a larger mattress.
| Bunk type | Width by length (inches) | What to know |
|---|---|---|
| Narrow bunk | 28 by 75 | A common narrow width |
| Standard bunk | 30 by 75 | A little wider than narrow |
| Wide bunk | 34 by 75 | Check that your frame has the room |
| Short bunk | 28 by 72 | Shorter than the usual 75 |
| Short wide bunk | 32 by 74 | Wider, but a little shorter |
| Double bunk | 42 by 80 | Much wider, and longer than most |
| Double bunk, wide | 48 by 75 | A wider double size |
Bunk frames vary, so measure the bunk you own rather than trusting a chart.
Mattress sizes for plain rectangular bunks
If your bunk is a straight rectangle, a foam replacement in a standard width is usually the simplest fit. The 28 by 75 FoamRush is one example of a narrow bunk, and it's 6 inches thick.
FoamRush makes its bunk mattresses in the USA, and they don't include a cover, so buy one separately if you want a washable layer.
The next FoamRush up is 30 by 75 inches and keeps the same 6-inch profile.
Wider double bunks
The 42 by 80 FoamRush is 8 inches thick, and FoamRush designs its gel memory foam layer to disperse body heat. The foam can take 3 to 4 days to fully expand after you unroll it, so plan the bed before the trip.
If your bunk is a twin-size platform instead, see RV full and twin mattress sizes for the matching widths.
How do you measure a bunk for a mattress?
Measure the platform width at both ends and the length down the middle, then check the height above the bunk. The width is the number that most often decides whether a mattress fits.
- Remove the old mattress, bedding and any loose boards.
- Measure the width at the head end and at the foot end.
- Measure the length down the middle and along both sides.
- Measure the height from the platform to the top of the guardrail.
- Write down every number before you order.
Measuring the frame is more reliable than measuring the old mattress, which may not match the bunk underneath. If the two ends don't match, use the shorter number for the width.
On a double-over-double bunk, measure the top and bottom berths separately, since the two may not match. For the full tape-measure checklist, read how to measure an RV mattress before you buy.
Common measuring mistakes
The biggest mistake is measuring the old mattress and assuming the bunk matches it. A few other slips are easy to make, too.
- Skipping the corners, where a cut or rounded frame changes the usable width.
- Measuring the length once, in the middle, and missing an uneven edge.
- Forgetting the guardrail height, which limits how thick the mattress can be.
What is a corner cut, and how do you measure one?
A corner cut is an angled or curved corner that removes part of the mattress so it fits around the bunk's shape. Corner cuts are most often needed on double-over-double bunks, where the frame's corner leaves no room for a square mattress.
To measure a cut, record the length of the angled edge, the length of each straight side, and which corner is cut. Measure from the corners of the platform, not from the wall, since the wall may not be square.
ZAQYCM builds its bunk mattress to your numbers: you send a photo with your measurements and say whether you need a left or right corner cut. Hand measurements can be off by 1 to 3 centimeters, so measure twice before you send them.
The custom mattress ships compressed, so give the foam a few hours to fully expand before you check the fit.
The cover unzips for the washer, and ZAQYCM rates the memory foam core medium firm.
Angled versus curved cuts
An angled cut has a straight diagonal edge, while a curved cut follows a rounded line that a straight edge can't match. A curved cut is harder to copy by hand, so a paper template helps before you order.
Our Camping World Cozyway curved bunk review looks at a curved option sized 50 by 74 inches, with 4 inches of foam.
How thick can a top bunk mattress be?
Follow the bunk maker's maximum mattress thickness and guardrail guidance, because the limit depends on the bunk itself. A thicker mattress raises your head closer to the ceiling and reduces the height of the guardrail above the mattress, so check both before you order.
The FoamRush bunks are 6 and 8 inches thick, and the ZAQYCM custom mattress comes in 2, 3 or 4 inches. For general bunk bed safety guidance, see the Consumer Product Safety Commission.
Weight matters on a top bunk too, since you lift the mattress every time you change the sheets. The FoamRush 28 by 75 weighs about 15.5 pounds, and the ZAQYCM in its 2-inch thickness weighs 11 pounds.
For height and clearance planning beyond the bunk itself, see how thick should an RV mattress be.
What should you check on a bunk mattress before you order?
Get the length and width in inches, the thickness, and the corner cut details before you order. Those numbers answer most fit questions.
- Length and width in inches, not just a bunk label.
- Thickness, so you can check it against the bunk maker's limit.
- The corner side and angle, for any cut mattress.
- Whether a cover is included, since the FoamRush bunks don't come with one.
- Whether the mattress can be trimmed, since the ZAQYCM custom mattress isn't meant to be.
If a size appears in more than one place, make sure the numbers match before you order.
Which bunk mattress should you buy?
Pick the size that matches your measured bunk, and pick a custom cut only when the bunk has an angled or curved corner. A square mattress that's too large for the platform won't fit, so don't round up.
- Pick a standard FoamRush foam bunk if your bunk is a plain rectangle that matches one of the sizes in the table.
- Pick the made-to-measure ZAQYCM if your bunk has a left or right corner cut.
- Pick the 42 by 80 FoamRush only if your bunk is the wider double size.
Timing differs between them. The 42 by 80 FoamRush needs 3 to 4 days to fully expand, while the ZAQYCM needs a few hours, so order the slower one first if a trip is coming up.
Next, read our best corner-cut RV bunk mattresses roundup to compare the other cut options.
Frequently asked questions
What size is a standard RV bunk mattress?
Common straight RV bunks take a mattress 75 inches long and 28, 30 or 34 inches wide, though sizes vary by maker. Measure your bunk before you order, because a mattress that's even slightly too wide won't drop in, and check the length too.
Do I need a corner-cut bunk mattress?
You need one only if your bunk has an angled or curved corner that a square mattress would hit. Measure the cut before you order, including the length of the angled edge and which corner it's on, since a custom cut is the safest option for an odd shape.
Can I trim a foam bunk mattress to fit?
FoamRush foam slices easily with a sharp or electric knife, but a cut usually can't go back, so trim a little at a time. ZAQYCM advises against trimming its custom mattress after delivery, so measure twice before you order or cut.
