King Size Mattress Size?

[ScottN]

The mattress in our 2022 Montana 3121RL is a non-standard size (even for an RV King); it measures 70”x80”. Soon after we placed the order for our RV, our salesman measured the mattress of a unit in their sales lot, and he told us it was 72”x80”. I assume other owners have discovered this, too. We want to buy a mattress topper, so looking for recommendations for sources.

(Does anybody have insight into when/why Keystone changed sizes?)

[DutchmenSport]

I don't know about your RV dealer, how he measured, if he did at all, or if he was just throwing something at you, but these are the standard mattress sizes:



But doing a quick Google search, I found this Click here.

Can I give you a word of advise here? Forget about getting a mattress topper and use the $150 (or more) toward a new comfortable mattress. Although there are some folks who sing praises about mattress toppers, our experiences have been less than favorable.

They slide around, they don't stay put, and they are a pain the neck. The often don't actually fit the actual size of the mattress, and after getting one, they are curl up and smother you (well, ... "me").

Do yourself a BIG favor and if the mattress in your camper is not comfortable, bite the bullet and purchase a new mattress that is comfortable for you. After all, you spend approximately 8 hours on it. That is 1/3 of your time. That is 56 hours a week (that's longer than a work week). That is 240 hours a month (using a 30 day month). That is 2920 hours a year you spend on the mattress. You don't even spend that much time on your employment, school, church, recreations, or watching television. So, why not do it right the first time, get a real mattress that's comfortable, dependable, trusted, and you know will last for years, and you won't be buying something different 6 months from now.

[mhs4771]

I don't know, but our RV King is 72x80

[Carl n Susan]

Our RV King and its replacement are 72" x 80"

[rohrmann]

Our RV King is also 72" X 80" with 12" radius corners at the foot of the mattress. We replaced the original, very heavy, inner spring mattress some years ago with a custom made latex foam mattress, the same dimensions and thickness, and are very pleased with it. We just use standard King sized sheets on it and have no issues.

[jcurtis934]

Latex foam is the best for comfortable, long life, etc. But the wife and I prefer different soft/hardness levels, so we went the sleep number route which is very good for my twisty spine. To really get good control of the settings, one must periodically run pressure down and back up to adjust for for when low and high pressure systems cycle through. John

[Bourbon County]

We tried the foam topper route too and experienced the same issues listed in this thread. They do move around a lot, fitted sheets don't stay on, etc. If you wish to try that route; I recommend buying a standard residential size topper and cutting it to size. Foam cuts pretty easily with a serrated blade knife like a bread knife. It won't be pretty and it's difficult to keep the cuts straight. There are numerous brands on the market and a good one will likely run >$100.

I'm in the camp that recommends buying a good replacement mattress. Carefully measure the bed platform at narrowest point rather than the mattress; I believe you'll find that it will accommodate a 72" wide mattress which is a more standard RV width. Another critical measurement is the max height. My Monty has a dorky little wall mounted shelf along both sides of the bed near the headboard; this limited me to a mattress <12" thick.

Some of the chain mattress stores can order an RV size mattress and have a sample on hand to try before you order. There are numerous online vendors that offer "highest rated RV mattress". I'm very Leary about making a choice that important and personal without trying it first. Most of the online outlets offer a satisfaction guaranteed warranty; I would love to see someone roll up a king size mattress to about 1 foot in diameter and 3 foot long to put back in the box. I don't see that genie going back in the bottle.

To me, the most important factor is finding something that has the same feel as what you're used to sleeping on. As mentioned Sleep Number makes RV mattresses; you can find memory foam as well as more traditional type mattresses. Let's face it, we buy 40 foot campers with appointments to resemble the look and feel as our homes for comfort. With the exception of maybe tires, this is the most critical upgrade for your camper. Take good measurements and shop around.

[ScottN]

I had a chance to measure our King mattress, and the salesman was correct — it is 70”x80”. We will try a mattress topper from MattressInsider.com because they can make this semi-custom size (although we are not the only ones to order from them with this unusual size).

[Gubs]

We have a 2020 Montana 3121 and the king mattress is 72X80

[Trevor]

We have a ‘21 3761fl and it is a standard size king mattress.

[skippydoo]

Perhaps by now you have worked out your mattress challenge. In case things are still up in the air:

We replaced our RV King with a regular wonderful Queen mattress from a local mattress store in town. Husband sawed off some of the platform and wala. Perfect fit.

More room to walk around the bed too.

We lug our mattress around when we buy a new rig. Dealer can keep their yucky mattresses. Toppers never worked for us.

[wed]

Check the mattress at LCI go on line.

[Hit The Road]

We traded our original mattress for 2-6 volt golf cart batteries during our PDI. We picked up a queen size Serta memory foam mattress from Lowes for $315.00! Did not want a king because there would be limited space to move around the bed in our 3121RL. And we didn't want to purchase "RV sheets". We use standard queen sheets and comforter's. Works very well for us!