Sleeping well in a Class A motorhome starts with the right mattress. Many owners discover with surprise that RV beds differ in size from home beds. One of the most common sizes found in Class A motorhomes is the Narrow King RV mattress. This guide will help you understand what it is, why it’s used, and how to choose the best option for your motorhome.
If you’ve ever woken up sore, cramped, or too hot in your RV, your mattress could be the problem. Let’s fix that.
What Is a Narrow King RV Mattress
A Narrow King RV mattress fits RV bedrooms with tight spaces. It has a king-style sleeping area, but it’s narrower. This design helps it fit better in Class A motorhomes.
Common Dimensions
Most Narrow King mattresses have a standard size, but sizes can vary by brand.
- 72 inches wide
- 80 inches long
This is narrower than a standard king mattress, which is usually 76 inches wide. That smaller width makes a big difference inside an RV.

Why Class A Motorhomes Use Narrow King Mattresses
Class A motorhomes are large, but the bedroom area still has limits. Builders must balance comfort, storage, and walking space.
Key Reasons for Using This Size
- Slide-out clearance: Bedrooms often sit inside slide-outs that limit width
- Walk-around space: Narrower beds allow room to move on both sides
- Weight control: RV mattresses must stay lighter than home mattresses
- Built-in furniture: Nightstands and wardrobes need space too
A narrower king-style mattress offers plenty of room without crowding your space.
How to Measure Your Class A RV Bed Platform
Before buying any RV mattress, measuring is critical. Never assume the size based on what the dealer tells you.
Step-by-Step Measuring Guide
- Remove all bedding and mattress toppers
- Measure the width of the bed platform
- Measure the length from headboard to foot
- Measure corner shapes if the platform is rounded
- Measure the greatest thickness allowed
Common Measuring Mistakes
- Measuring the old mattress instead of the platform
- Forgetting slide-out clearance
- Ignoring curved corners
Even a one-inch mistake can cause major fit problems.
Narrow King vs RV King: What’s the Difference
Many RV owners confuse these two mattress sizes.
RV King Mattress
- Usually 72 x 80 inches, but sometimes wider
- Common in fifth wheels and larger RVs
Narrow King Mattress
- Reduced width by a small amount.
- Designed for tighter Class A bedrooms
If your RV bedroom feels tight, the narrower option usually works better.
Best Mattress Types for Class A Motorhomes
Choosing the right mattress material is as important as size.
Memory Foam
- Lightweight and RV-friendly
- Good pressure relief
- Can trap heat if low quality
Best for side sleepers and couples.
Hybrid Mattresses
- Foam + coils
- Better airflow
- Stronger edge support
Good for people who toss and turn.
Latex Mattresses
- Naturally cool
- Very durable
- Heavier than foam
Works well for full-time RV living.
Innerspring
- Traditional feel
- Heavier and less flexible
- Can wear out faster in RVs
Not ideal for most motorhomes.

Mattress Thickness and Weight Matter
RV bed platforms are not built like home bed frames.
Ideal Thickness
- 8–10 inches for most Class A motorhomes
- Thicker mattresses may block cabinets or windows
Weight Considerations
- Heavier mattresses stress slide-outs
- Lightweight foam is easier to lift and rotate
Always check your RV manufacturer’s recommendations.
Airflow and Moisture Control in RV Mattresses
Moisture is a hidden problem in RVs. Without airflow, condensation can lead to mold under the mattress.
Signs of Poor Ventilation
- Musty smells
- Damp mattress bottom
- Mold or mildew spots
Simple Solutions
- Mattress ventilation mats
- Slatted bed platforms
- Moisture barriers
These small upgrades can extend mattress life and protect your RV.
Common Problems RV Owners Face
Finding Sheets
Standard king sheets may be too loose. Look for:
- RV-specific king sheets
- Adjustable elastic sheet sets
Heat Retention
Foam mattresses can sleep hot. Look for:
- Gel-infused foam
- Breathable covers
Edge Support
Some foam mattresses collapse on the edges. Hybrids usually perform better.
Accessories That Improve Sleep Comfort
You don’t always need a brand-new mattress to sleep better.
Helpful Add-Ons
- Mattress toppers for firmness changes
- Waterproof mattress protectors
- Breathable mattress pads
These can fix comfort issues without replacing the mattress.
Buying Tips for RV Owners
When shopping for a Narrow King RV mattress, focus on RV-specific features.
What to Look For
- Lightweight materials
- CertiPUR-US certified foam
- RV-friendly thickness
- Good return policy
What to Avoid
- Heavy residential mattresses
- Poor ventilation designs
- No warranty or trial period
Always confirm exact dimensions before ordering.
Frequently Asked Questions
Can I use a regular king mattress in a Class A motorhome?
Usually no. A standard king is often too wide and heavy.
Can I order a custom RV mattress?
Yes. Many RV mattress companies offer custom sizing.
How long should an RV mattress last?
Most RV mattresses last 5–8 years, depending on use.
Final Thoughts
Choosing the right Narrow King RV mattress can transform your sleep in a Class A motorhome. The right size, material, and thickness help you sleep cooler, move easier, and wake up pain-free.
Measure your bed platform. Think about weight. Check airflow. Use materials meant for RVs. A good night’s sleep makes every trip better.

