How to Cut a Memory Foam Mattress (Step-by-Step Guide)

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You want to cut your memory foam mattress to fit your van, or maybe an unusual bed frame. Whatever your reason might be, we’re here to help you do it. Our team spent dozens of hours researching the topic and came up with a step-by-step guide on how to cut a memory foam mattress. Read the full article below.

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How to cut a memory foam mattress

We’ve put together several steps to cut your memory foam mattress and achieve the specific dimensions that you need. These steps are in order so you have to do the top one first then move on to the next one. Before you start, remember that cutting memory foam mattresses will definitely void their warranties. If you understand that and you still wish to proceed, follow the steps below. Keep in mind that this guide is only for memory foam mattresses. This guide won’t work if you have a mattress without memory foam.

Step 1: Gather your tools

First, you have to gather the tools and materials that you’ll be using. The most important tool is your cutting tool. Then, you should also prepare materials for measuring and marking the dimensions that you want for your customized mattress.

Step 2: Determine the size of the mattress that you want

This will depend on your reason for cutting your mattress. Whether it’s for your boat, van, RV or an unusual bed frame, make sure to measure the area where you intend to put the mattress first. This will give you a clear idea of the mattress size that you need.

Step 3: Remove the mattress cover

Take off the cover of your mattress. If it has a non-removable cover, use a seam ripper to remove it so you can access the foam directly.

Step 4: Measure and mark the areas you want to cut

Use a tape measure or ruler to measure the dimensions that you need. Double-check the height, width, and thickness of the memory foam needed. After that, mark the mattress with a marker pen to create an outline of where your cuts will be. We recommend adding an extra 1/8 inch on your measurements since cutting the foam will most likely remove some of its material.

Step 5: Cut the foam mattress on a flat surface

Setting the mattress on a flat surface before cutting it is important because you want to get clean straight edges. Make sure the surface is steady so you won’t compress the foam while you cut it. You can also put something heavy on top of the mattress to hold it in place while you cut it.

Step 6: Trim off any excess and replace the cover

After cutting the mattress and measuring out your preferred dimensions, make sure to trim off any excess material. Then you have to decide whether you want to buy a new mattress cover or use the old cover. If you decide to use the old one, a sewing kit may come in handy to make some adjustments.

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What tools you need

These are the following tools that you will need to cut your memory foam mattress. Most of these materials can be found in your home. Preparing these tools and materials is the first step that you’re going to have to do before you start cutting your mattress.

Type of knife

To cut a memory foam mattress, heavy-duty tools aren’t really necessary since the foam is quite flexible. A sharp knife is more than enough to do the trick. Here’s a list of the different knives that you can use to cut your memory foam mattress:

• Electric knife – This knife is probably the easiest one to use. It has serrated edges and all you have to do is simply slide the knife through the foam while following your outline. You can expect very clean and defined cuts if you use an electric carving knife.
• Carving knife – This knife also features serrated blades which are key to getting a clean edge. Use gentle back and forth motions to cut through the foam to avoid applying too much pressure and compressing it.
• Utility knife – This knife is very sharp and it has a pointy tip that makes it easier to go through the foam. However, instead of sawing through the foam, you’re going to have to make light passes to cut the foam. Make the cut gradually deeper until you reach the bottom and cut through the foam.
• Heavy-duty scissors – If you don’t have a suitable knife, you can use heavy-duty scissors. Cut smaller portions of the memory foam and be careful not to snip your fingers. Scissors are also great for cutting memory foam mattress toppers that are thinner than foam mattresses.

Other tools

Some additional tools you might need are:

• A ruler or measuring tape
• A marking pen
• A seam ripper
• A sewing kit
• A drywall square or a piece of plywood

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What can you use to cut a memory foam mattress horizontally?

If you want to make your old memory foam mattress thinner, then it has to be cut horizontally which is quite difficult. You’re going to have to be very precise, and you’ll need some special tools. Below are some tools you can use to cut your memory foam mattress horizontally.

Use a large horizontal saw

Hold the top part of the foam but don’t apply too much pressure on it. Then, gently move the saw through the foam. We recommend putting your mattress on a sheet or towel as foam bits might fly around in the process. It will make the cleaning process much easier for you.

Use a hot wire

With this option you might need some extra help, preferably from steady hands. Place the mattress on a taller base to make it more convenient for you.

That being said, we don’t recommend cutting your memory foam mattress horizontally. There’s a high chance that you might damage the foam, and there’s no guarantee that your customized mattress will still deliver the comfort and support that you need. Instead of taking the risk, you can always get a new memory foam mattress that suits your needs and preferences.

Check out our best memory foam mattresses list for our top recommendations.

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Reasons for cutting a memory foam mattress or mattress topper

• To put it on a smaller bed
• To fit it to an unusual area such as a boat or an RV van
• To split a bigger mattress into two smaller ones
• To customize a mattress for a non-standard bed frame
• To use the excess memory foam to make makeshift pillows, seat cushions, padding etc.

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FAQs

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Conclusion

All things considered, it is definitely possible to cut and customize your memory foam mattress in your own home. Just follow our step-by-step guide and you’ll do just fine. Although we don’t recommend cutting your memory foam mattress horizontally, you can still do it with the tools that we mentioned above.

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Next step: Read our list of mattresses brands with buy now, payer later financing. If cutting your mattress to size is too much work, buying a new one is the way to go. Each brand on this list is available to ship immediately with no up-front cost.

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Psst… the sleep review industry is full of liars, sharks, and thieves. It’s a modern-day version of getting ripped off at your local mattress store. So, why should you trust us?