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DIY Custom RV Mattress

Is the camper mattress that came in your RV uncomfortable? Do you want a better night’s sleep while camping? Get a new one with this Custom RV Mattress mod.

before and after of an RV mattress replacement

One of the biggest complaints that people have about RVs is the sucky mattresses. The foam used by the manufacturers is thin and does not offer much support.

You can order a custom mattress, but they are expensive! This is true when you realized that RV Mattress Sizes vary from model to model.

You can do your own custom foam mattress the size you need for your RV.

thin queen RV mattress inside a motorhome

How to Save Money on a Custom RV Mattress

Our brand new class C motorhome came with a 4” piece of foam for the queen mattress. We slept on it one night and realized that we need to change it right away.

Since we dropped a bunch of money on the purchase of the RV, so we did not want to spend a lot on a new bed. We found a sale and got an 8” memory foam Serta mattress from Sam’s for $200. The bed in a box included free delivery, which made this project much easier.

memory foam mattress in a box

memory foam mattress from a box laid out on a bed in a camper

Can you cut a memory foam mattress?

Have you ever wondered if you can cut a memory foam mattress? The answer is yes! It can be a messy process, but so worth it to get the desired size of bed. Particularly in an RV.

PLEASE NOTE! Check the tag of your mattress before attempting to cut.
If it contains fiberglass DO NOT CUT IT!

cutting a memory foam to create a custom RV mattress

The process is easy! We cut ours in place in our camper.

If your bed is in a tight spot that will make cutting difficult, you can open the mattress elsewhere and use the old mattress as your cutting guide.

We only had to make one cut for our bed. We started with a utility knife, switched to a long serrated knife, and finally discovered that a big straight knife worked best.

Electric knives work well for cutting memory foam mattresses.

custom foam mattress for an RV

We are so happy to have a regular mattress in our camper! Good sleep is a treasure, especially when you are away from home.

We use a regular queen-size sheet on this corner-cut mattress. We tuck the looseness underneath.

After shot of a custom RV mattress replacement

RV Bunk Mattress Replacement

The over-cab bunk mattress on our brand new motorhome is even more uncomfortable than the main bed mattress. Our 100-pound child created a dent in it after two nights.

We used the main bed foam to replace the over the cab mattress. This was a little trickier because of the size of this bed.

I ended up replacing the part that our daughter sleeps on. She is more comfortable now.

This is done the same way. I removed the cover on the foam, laid the replacement on top, marked the cutting lines on both, cut, replaced, and put the cover back on. This was a much messier process than the regular mattress.

Unless someone crawls around up there above the cab, you do not even notice the replacement. We plan to keep this RV for a long time (if you know our track record, you will laugh), so we are trying to keep it as intact as possible.

custom motorhome mattress for overhead bunk on the outside of an RV

Where do you get sheets for an RV mattress?

I used the flat sheet from the queen sheet set that I purchased for our RV bed to create a custom sheet for this upper bunk. It is easy to turn a flat sheet into a fitted sheet. If you do not sew, then get RV sheets online.

Instead of an RV mattress replacement, many people just add a topper to their crappy RV mattress. That is not satisfactory for us! Camping is our ultimate relaxation time, so we need a regular thick mattress. A regular bed was a consideration when we picked out our new RV.

man standing the doorway of a motorhome holding a piece of foam

What do you do to get a comfortable night’s sleep when you camp? Make your own RV foam mattress and sleep well tonight!

Check out our other RV hacks: Running Lights On While Parked or Trailer Tongue Storage Mod.

collage showing before and after of a DIY camper mattress replacement

Yield: 1

Custom RV Mattress

a custom cut in a memory foam mattress in an RV

You can create your own Custom Camper Mattress with this easy to follow tutorial. No more uncomfortable nights in your RV!

Prep Time 2 hours
Active Time 30 minutes
Total Time 2 hours 30 minutes
Difficulty medium
Estimated Cost $300


  • 1 memory foam mattress in a box *see notes below


  • measuring tape
  • marker
  • long knife


    1. Measure the mattress you want to replace.
    2. Get a mattress in a box that is larger than this mattress.
    3. Remove the old mattress.
    4. Open up the new mattress and roll it out where it will go in your RV.
    5. Let the mattress expand.
    6. If there is a mattress cover, remove it.
    7. Mark the cut line(s) with a marker. Use the old mattress as a template.
    8. Use a long knife to cut down the mattress along the lines.
    9. Replace the mattress cover.
    10. Enjoy your upgraded mattress!


PLEASE NOTE! Check the tag of your mattress before attempting to cut. If it contains fiberglass DO NOT CUT IT!

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Did you make this project?

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Wednesday 19th of July 2023

I have done upholstering and found the best a easiest way to cut foam is using an electric knife.

Jody B

Monday 13th of June 2022

I have that exact same Coachmen and need a new mattress. I will definitely try this. Thank you so much for the helpful post!

Diana Hansen

Monday 13th of June 2022

Happy Camping, Jody!


Saturday 19th of February 2022

Please inform your readers about the danger of fiberglass in many foam mattresses. It has been known to cause thousands of dollars worth of damage to homes and is dangerous to breath in. Manufacturers put it in as a fire retardant and many of the mattresses tags will say if there is fiberglass in them and advise not taking off the cover.

Diana Hansen

Saturday 19th of February 2022

EXCELLENT advice, Jim! Adding a clear warning now.

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