RV Mattress Sizes and Replacement: Short Queen, RV King, Bunks and Cut Corners

The mattress that came with most RVs and campers is thin, basic and sized for the floor plan, not for your back. Replacing it is one of the best comfort upgrades you can make, as long as you measure for the RV you actually have.

RV sizing is where most replacement mistakes happen. Names like “short queen” and “RV king” are common, but they aren’t perfectly standardized across manufacturers. This guide walks through the common sizes, how to measure properly, and the RV-specific problems a home mattress never has to deal with.

Common RV mattress sizes

These are typical dimensions you’ll see listed. Treat them as a starting point and confirm with your own tape measure, because floor plans and manufacturers vary.

How to measure an RV bed properly

1. Remove the old mattress and measure the platform itself, wall to wall or edge to edge.
2. Measure width at the head, middle and foot. RV walls aren’t always square; use the smallest number.
3. Measure length on both sides for the same reason.
4. Note any cut or rounded corners. Measure how far the cut starts from each edge, or trace the corner on cardboard.
5. Measure height clearance: from platform to the lowest overhead cabinet, window ledge or trim you’d hit sitting up.
6. Check slide-out travel. If the bed is in a slide, retract it and see how much room remains above and at the foot of the mattress.
7. Check lift storage. If the platform hinges up on gas struts, note how much weight they’re designed to lift.

Write all of this down before you shop. A good tape measure and a phone photo of each measurement saves arguments with yourself later.

Cut corners and custom shapes

Many RV beds, especially in the front of fifth wheels and in some travel trailers, have angled or radiused corners to clear walkways or doors. Your options:

• Buy a corner-cut model if one is sold in your exact size and cut.
• Buy a rectangular all-foam mattress and accept a slight overhang if the corner is small and the foam is flexible enough to tuck.
• Trim foam yourself. All-foam mattresses can be cut with an electric carving knife, then re-covered. This will almost certainly void any warranty, and a hybrid or innerspring with coils should not be cut.
• Order custom. Custom RV mattress makers exist; expect longer lead times and stricter return terms.

Which mattress type suits RV life?

Weight is a real consideration in an RV. Every pound counts against your cargo capacity, and lift-up beds rely on struts sized for a certain load. If you go heavier, you may need stronger replacement struts.

Thickness and clearance

Thicker isn’t automatically better in an RV. A taller mattress can:

• Stop a slide-out from retracting if the mattress hits a wall or cabinet.
• Leave too little headroom to sit up comfortably in a low bedroom or cab-over bunk.
• Overload lift-storage struts.
• Make bunk guardrails less effective, which matters for kids.

Choose the thickness that fits your clearance first, then pick the best feel available at that thickness. A good mid-thickness foam mattress usually beats a very thick one that won’t let the slide close.

Condensation: the RV-specific problem

RV bed platforms are usually solid plywood, and RVs build up humidity from breathing, cooking and showers in a small space. When warm, moist air meets a cool platform under a mattress, condensation can form. Over time that can lead to mildew on the underside of the mattress or the platform.

Ways to reduce the risk:

• Use a breathable spacer underlay, such as a 3D mesh anti-condensation mat, between platform and mattress.
• Lift the mattress periodically to check the underside and platform, especially after cold nights.
• Run ventilation fans or crack a vent when cooking and showering.
• Consider a small dehumidifier or moisture absorbers for humid climates and winter camping.
• Choose a mattress protector that breathes reasonably well.
• When storing the RV, prop the mattress up or open lift storage to let air circulate.

Upgrade without replacing: toppers in an RV

If the original mattress is still supportive but thin or firm, a topper is a cheaper upgrade. Order it in the same RV size (a short queen topper for a short queen bed) so it doesn’t overhang. Remember that a topper adds to the total height, so the clearance rules above still apply. Foam toppers are lighter than latex, and a breathable cover helps with the condensation issue below the mattress as well as heat on top. If the stock mattress is already sagging, though, a topper will sag with it; that’s the signal to replace.

Sheets and bedding for RV sizes

A home queen fitted sheet on a short queen mattress will bunch at the foot. Options:

• Buy RV short queen sheets sized for the shorter length.
• Use home queen sheets with sheet straps to take up the extra length.
• For cut corners, look for sheets labeled for corner-cut RV beds, or use a flat sheet tucked in.

For bunks with odd sizes, flat sheets and sleeping-bag style covers are often easier than hunting for exact fitted sizes.

Before you click buy

• Width, length and corner shape match your measurements.
• Thickness fits slide-out and headroom clearance.
• Weight works with lift struts and your cargo capacity.
• Return policy covers RV sizes (some odd sizes are final sale).
• You have a plan for getting it through the RV door; boxed mattresses help here.
• Warranty terms don’t exclude use in vehicles or require a support type your platform can’t meet.