by Memory foam is a space-age material often used for mattresses and mattress toppers. While comprehensive scientific studies are lacking, evidence suggests that memory foam mattresses improve sleep and are helpful against back pain. It can be hard to find memory foam mattresses pre-cut to fit your requirements. If you’re looking to customize your mattress to fit your space, here is how to cut memory foam mattresses and mattress toppers.
To cut your memory foam mattress or mattress topper, follow these steps:
- Determine the size and dimensions of the mattress that you want.
- Take off the mattress cover.
- Use a ruler, a marker pen, and a sharp knife to measure and mark where you want to cut.
- Cut the memory foam mattress or mattress topper carefully on a flat surface without compressing it.
- Trim off the excess and (re)fit the mattress cover
Related articles:
- What’s the difference between latex vs. memory foam mattress toppers?
- What’s a copper mattress pad and what are the benefits?
“What type of mattress to get for your camper van and how to cut it.” Photo credit: Parked in Paradise. Why Cut Memory Foam Mattresses and Mattress Toppers?
You may want to:
- Turn two twin size beds into one using an overlay of a king-sized mattress.
- Fit a memory foam mattress to an unusual area, such as inside a boat, the back of a van, or you might want to put the mattress topper on top of an air mattress.
- Turn a king-sized mattress into two singles.
- Customize your foam mattress for a frame with an unusual size.
- Customize the size and shape of your mattress.
- Re-use parts of a cut-down foam mattress for other applications, such as packaging material, makeshift pillows or mats.
Once you cut your memory foam mattress topper, you might be wondering, how do you protect a mattress topper or mattress pad that you lay on top of your mattress. We’ve got you covered.
Related articles
- Can you put a mattress pad on top of a foam mattress?
- What’s the mattress topper hack and how does it save you money?
How to Cut a Memory Foam Mattresses and Mattress Toppers
IMPORTANT NOTE: Cutting your foam mattress will, in most cases, void the manufacturer’s warranty.
Make sure you have a ruler, a marker pen, and a sharp knife.
You will need the following tools to take measurements: long ruler or tape measure, marker pen, and a sharp knife. (You can go to a hospitality shop to get your knife sharpened professionally or use a knife sharpener.)
Determine the size and dimensions of the mattress that you want.
Consider the thickness you want to have. If you are fitting your memory foam mattress into a smaller space, like a boat or van, it should not be too tall. Since memory foam can be flattened easily, it may be better to have a medium density overlay on top of a very high-density mattress. This will prevent the mattress from flattening but ensure comfort. Some brands of memory foam are designed with this in mind and will have layers with different types of memory foam.
Before you cut, you also need to consider the dimensions you want. How much head and foot space are needed? These considerations are especially important when custom cutting a foam mattress for a boat or van. Here is a list of different bed types and their measurements for your reference.
| Mattress type | Size |
| Twin | 38” x 75” |
| Twin XL | 38” x 80” |
| Full | 53” x 75” |
| Queen | 60” x 80” |
| King | 76” x 80” |
| California King | 72” x 84” |
Take off the mattress cover.
If your memory foam mattress has a cover, take it off first and put it somewhere safe and clean. Some mattress covers may need to be cut open. If this is the case, use a pair of cloth scissors. Make an initial cut to get into the cloth, then press it against the fabric to make a vertical cut along the short edge of the mattress. Only cut as much as it is necessary to take the foam mattress out. Before you cut any fabric, check for zippers, as most factories add zippers.
Measure and mark where you want to cut.
Measure and use a ruler to draw the line of the cut you wish to make. Make indents every 18 to 24 inches. Drywall squares are perfect for cutting long pieces of foam straight. Alternatively, you could measure out the desired dimensions onto cardboard, and use it as a template for your foam cutting job.
Cut the memory foam mattress or mattress topper carefully on a flat surface without compressing it.
Make sure the foam mattress is on a flat, stable surface.
Before cutting, make yourself aware of the angle of the blade. The blade should be parallel to the height of the mattress, unless you want to cut the mattress in half horizontally (please see the below section for this) or create an unusual shape.
When cutting do not put pressure on the area where you are trying to cut the line. DO NOT compress it, as the shape will be changed! If your knife is too short to cut all the way through, simply make a shallow cut followed by a deeper cut. Bear in mind that the bottom section of memory foam may be a different density, which will affect your cutting action. Harder foam is harder to cut, but soft foam is more likely to move or warp out of place. Thus, if you are cutting soft foam, place something on either side of it, like drywall squares or cardboard, to avoid warping the mattress.
Check the line to see that the entire length has been cut through. The mattress may be thick, so make two cuts if necessary. Do not flip the mattress over unless you are sure that the line on both sides will be the same.
Related topic:
- How long does it take memory foam to expand?
- How to use and clean a mattress topper
- The in-depth guide to choosing a mattress topper.
Trim off the excess and (re)fit the mattress cover.
Trim off excess, but do not worry too much about presentation as you will be able to put the mattress cover back on. Since the mattress is now smaller, decide whether you want to buy a new cover, re-stitch the old one with a sewing machine or fold over the excess cloth. Think about what you will do with the excess material before you cut it into too many small pieces, as it could be useful for making another mattress, a mat or a pillow. Your options will decrease the smaller the leftover pieces are.
How to Cut Memory Foam Mattresses and Mattress Toppers Horizontally
IMPORTANT NOTE: Cutting your foam mattress will, in most cases, void the manufacturer’s warranty.
Cutting memory foam mattresses and mattress toppers horizontally is very difficult. Note that it is especially important in this case not to put too much pressure on the mattress when cutting, as this will distort the shape. To ensure a straight line throughout the width of the foam, it is necessary to prevent the mattress from moving while you cut. It is therefore recommended to find a foam shop where you can have your mattress cut to your required dimensions for you.
To cut a memory foam mattress horizontally, try these methods:
- Cut your memory foam mattress with a large, horizontal saw.
- Use a hot wire to cut horizontally through your memory foam mattress.
- Use an electric saw to cut horizontally through your memory foam mattress.
Cut your memory foam mattress with a large, horizontal saw.
The most efficient way to cut memory foam mattresses and mattress toppers horizontally is to use a large horizontal saw. Foam shops such as Mr Rubber have these, but if you are unable to access such a business, you will need to contrive your own wide foam cutting device.
Use a hot wire to cut horizontally through your memory foam mattress.
You could make a hot wire wide enough to cut through a twin or king size mattress, depending on your needs. However, since hot wires need to be used with a very firm and steady grip, you will need to make a very large base, along with a platform to put mattresses on. It will take up a lot of space and time, which will be wasteful unless you are planning on starting a business.
Use an electric saw to cut horizontally through your memory foam mattress.
To use an electric saw to cut memory foam mattresses and mattress covers horizontally, follow these step:
- Determine the size and dimensions of the mattress that you want.
- Take off the mattress cover.
- Make sure you have a ruler, a marker pen, and measure your saw blade so you know how deep it cuts.
- Measure and mark where you want to cut.
- Cut the memory foam mattress or mattress topper carefully on a flat surface without compressing it.
- Trim off the excess and (re)fit the mattress cover.
Determine the size and dimensions of the mattress that you want.
Consider the thickness you want to have. If you are fitting your memory foam mattress into a smaller space, like a boat or van, it should not be too tall. Since memory foam can be flattened easily, it may be better to have a medium density overlay on top of a very high-density mattress. This will prevent the mattress flattening but ensure comfort. Some brands of memory foam are designed with this in mind and will have layers with different types of memory foam.
Take off the mattress cover.
If your memory foam mattress has a cover, take it off first and put it somewhere safe and clean. Some mattress covers may need to be cut open. If this is the case, use a pair of cloth scissors. Make an initial cut to get purchase into the cloth, then press it against the fabric to make a vertical cut along the short edge of the mattress. Only cut as much as it is necessary to take the foam mattress out. Before you cut any fabric, check for zippers, as most factories add zippers.
Make sure you have a ruler, a marker pen, and measure your saw blade so you know how deep it cuts.
You will need the following tools to take measurements: long ruler or tape measure, marker pen, an electric saw, and an electric saw blade. It is important that you measure the blade of your saw to find the depth of foam it can reach.
Measure and mark where you want to cut.
Measure the foam needing to be cut. Make indents on the foam to see how many cuts will need to be made. Make straight lines where the cuts need to be made, using a different colour so that you will not get confused.
Cut the memory foam mattress or mattress topper carefully on a flat surface without compressing it.
Place the mattress on a flat surface. Use a level to make sure that is is completely flat to ensure that you will not be cutting at an angle. This step is especially important, because when you are cutting a mattress horizontally, sloped cuts are far more noticeable.
Make the first cuts on the outer edges of the mattress, keeping your grip firm and the steady on the electric saw to maintain the line.
The first inner cuts should be made on the corners. Ask a friend to gently hold the flaps open while you insert the blade smoothly. Progressively move to the parts which are easiest to hold apart whilst cutting through and maintaining a straight cut.
Trim off the excess and (re)fit the mattress cover.
When you are finished cutting through all the horizontal parts, trim off any excess bits. If you are using harder foam, be careful not to cut too deeply here, as it may result in a poor surface consistency. If this occurs, just do not sleep on that side. Since the mattress is now smaller, decide whether you want to buy a new cover, re-stitch the old one with a sewing machine or fold over the excess cloth. Think about what you will do with the excess material before you cut it into too many small pieces, as it could be useful for making another mattress, a mat or a pillow. Your options will decrease the smaller the leftover pieces are.
Related articles:
Which Kind of Knife Should You Use to Cut Memory Foam Mattresses and Mattress Toppers?
You may use a serrated or non-serrated knife. A serrated knife will be easier cut in a sawing motion, but it will leave a serrated pattern on the surface of the foam after you have cut it. On the other hand, if you have a non-serrated knife which is sharp enough you will only need to pull your hand slowly through the material as you are cutting, pausing to take out the knife and get a better grip.
If the mattress is thin enough, you may use heavy duty scissors or shears. Utility or craft knives are also useful because they are very sharp.
Electric knives and saws are easier but remember that you will also need to keep the foam in place to avoid distorting the material.
You may use a hot wire. This is very good for carving intricate shapes out of harder density memory foams, but you will need to be very careful and steady using this piece of equipment. If you stop, the foam will melt in one spot and may look messy. Generally, it is not necessary to use a hot wire unless the foam shape is small, and the density is very hard.
Having a sharp knife is a priority when cutting memory foam mattresses and mattress covers. Photo credit: My Sunday Tools.Memory Foam Cutting Services
Generally, when you pay someone to custom cut foam for you, you will have to buy the foam from them as well. You may find a list of prices on this site to get an idea of what it will cost.
Here is a list of the different densities of foam that you can buy:
- Soft: good padding material, or to add a little springiness between layers of harder foam.
- Medium: May be used for many of the same applications as the soft form but lasts longer. It has a longer shelf life than soft foam. Additionally, it is more suitable in baby mattresses, as it is lighter than the hard foam, but will not conform to the shape of a baby’s face and suffocate it.
- High: good for day beds and outdoor beds. Has a longer shelf-life.
- Very high: perfect for vans, as it won’t be flattened too easily. Has the longest shelf-life, with warranties lasting 10 years.
Foams may contain the following extra materials
- Gel: These mattresses are designed to help keep the body’s temperature down. Because it is a good insulator, it does not absorb as much body heat.
- Fibreglass: Acts as a fire retardant in the mattress. The fibres may come off and get into your skin as you are cutting it, so wear protective gloves.
When hiring foam cutting surfaces, it is critical to maintain good communication. Topics of your negotiations may include the following: The dimensions of area you wish to cover with mattress, the intended usages of the mattress, and of course, the cost of the materials as well as the cutting service.
Since most foam cutting services are included in the price of the foam, you will typically need to go to the shop where you bought the foam and ask them to cut it for you. If you bought the foam mattress online, you may approach a foam store and ask for a quote. If it is a simple job, foam shops may help you for free.
When considering the cost of the labor involved in cutting foam, understand that this is skilled labor, and should be at least twice that of the minimum wage in your country. For the United States, this should be $15 per hour. However, negotiate with your contractor for a price that is acceptable to both parties.
Cutting Memory Foam Mattresses vs. Memory Foam Pillows or Mattress Toppers
Regardless of whether the bedding product is a pillow, mattress topper or mattress, the principles of cutting are the same. You need to choose a sharp knife, make precise, straight cuts, and cut off loose ends. You need a stable and flat surface area on which to cut the foam with precision and delicacy. In all cases, you will need to cut the foam with appropriate levels of pressure, depending on the density of the foam and other materials used. Additionally, it is always necessary to practice safety with cutting tools and use protective gear when necessary. If the foam is deeper than the length of blade this will require holding open the flaps of the already cut sections, and it is therefore advisable to do these projects with a friend or helper.
Like mattresses, foam pillows also have cloth protectors on them, and may be restitched after the cutting is completed. Be sure to ease the cover back on after restitching, to prevent tears.