How to Cut a Memory Foam Mattress

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Written by: Anna Chiranova
Last updated on

Memory foam mattresses are great for a comfortable night’s sleep without back pain. These mattresses are, however, a little too dense, and that’s what makes their supporting effect for the body. For a lot of reasons, you might want to cut your memory foam mattress horizontally or vertically. Good news is that you can easily do it yourself using cutting tools, tapes, and a pen. In this article, we will elaborate more on how to cut a memory foam mattress simply.

What tools do you need to cut a memory foam mattress?

The reason why you need special tools for cutting a memory foam mattress is that if you use the wrong tools, you might get bad edges and cuts due to the fact that the memory foam compresses. This makes it hard to cut it straight up. Here are some recommended tools.

Carving Knives

Carving knives are perfect for cutting out clean edges due to having serrated blades. Normal knives apply too much pressure and take lots of grinding, so they tend to make memory foam cuts very uneven. However, carving knives with serrated blades causes a straight and clean cut as a result of a back-and-forth movement along the line.

Electric Knives

Electric knives also have serrated blades. You can simply put the blade next to the line and drag the knife along the line to cut it in a clean shape. 

Heavy-Duty Scissors 

These scissors can be used to cut through thinner layers of memory foam. They’re easy and result in clean cuts with not too much hassle. If you’re thinking of cutting your memory foam mattress topper, these are great tools.

Utility Knives

Utility knives are exceptionally sharp. They don’t have a serrated edge, but due to their sharpness, they can easily and smoothly cut a memory foam mattress, to the point that you don’t have to put any effort into cutting, and the measurement matters most. You can simply start cutting a surface outline and gradually cut deeper through the layer.

Protective Equipment

Since memory foams might have volatile organic compounds (VOCs), it is best to wear gloves and a breathing mask, and protection glasses. [1] It is also recommended to have a sheet of cloth beneath the memory foam mattress or around it, since there will be lots of small pieces of memory foam as a result of cutting it, and you don’t want to deal with cleaning them or taking them off the floor one by one. You might also want to keep the windows open in the room where you cut your mattress, just like when you open the best mattress in a box in Canada for the first time.

Ruler or Tape Measure

To be able to cut straight through the memory foam, you will need a measuring tool like a tape measure, a ruler, or even a long straight piece of hardboard. You can also use a pen to draw out a template and easily cut through the lines with the knives.

How to cut a memory foam mattress

Step 1: Measurements and Creating an Outline

You might say that you are good at freehanding it and cutting through the memory foam using following the line of your sight. However, it is better not to risk such things as you might find yourself trimming off so many edges and not reaching a straight edge. Therefore, it is better to use the tape measure or ruler to check the width, height, and depth that you need. 

While you are measuring the mattress and creating the outline, make sure you don’t compress the mattress as that can completely change the dimensions. When you are done measuring, draw an outline using a pen without compressing the mattress, and then double check everything to make sure the skeleton is fine.

Step 2: Cutting through the Outline

When you have a blueprint ready, it is time to grab your carving, electric, or utility knife and according to the functionality of each of them begin to cut through the mattress. Firstly make sure the mattress is on a flat surface and you are not compressing it. Try to keep the mattress in place to avoid cutting in the wrong directions. Nowadays, the best memory foam mattresses in Canada have different memory foam layers with different levels of density, so you should be careful how you cut through them.

If you are using a carving knife, simply go back and forth deeper and deeper. In the case of an electric knife, you can simply place the knife on the outline and cut through it. For a utility knife, make shallow cuts and go deeper slowly. If the mattress is too thick to cut through both sides accurately, you might want to flip the mattress over and also have the same outline on the other side. 

Step 3: Trimming the Uneven Edges

After you are done cutting, check for any excess or uneven edges that you want softened. Make sure you are not over-trimming it, though, as it might affect the density of the mattress. If you use a mattress cover, then you can simply ignore the trims that are mainly for visual beauty.


Can you cut a memory foam layer horizontally?

Yes, however, it can be hard to get it right. To do so, you need to do it very precisely while holding the mattress vertically.

Is it possible to glue back the memory foam pieces while cutting it?

Yes. If you ever make a mistake while cutting, you have to use an adhesive spray to glue the pieces back together.


Some people need to cut a memory foam mattress so they  can adjust it to their bed frame, to their desirable thickness, or density. Cutting a memory foam mattress can be done using simple tools that we all might have at home, such as a utility knife. Make sure you take lots of precision and protection into your work so you don’t cut through the mattress in the wrong direction.

Thank you for reading this article, and hope it has provided you with useful information to make a choice. Feel free to share your thoughts and experience with us in the comments.


  1. Volatile Organic Compounds. Retrieved from,they%20are%20in%20the%20air.

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