Making it a popular bedding choice, mattress foam is comfortable and versatile.If you want to cut mattress foam, the process is very simple and fast.A sharp knife and some basic tools are all you need.
Step 1: The zip cover needs to be removed from the mattress foam.
The outer covering on most mattress foam protects the foam inside.Pull the cover off if you want to remove it.Use a pair of scissors to remove the additional lining underneath the zip cover.You don't want to cut into the mattress foam with the scissors.Since the zip cover won't fit your mattress foam after you cut it, you can either dispose of it or try to reuse it.If you throw out the old zip cover, you will need to buy a new one.
Step 2: Measure tape to figure out where to cut the foam.
Measure from one side of the foam to the other and divide that number in half to figure out where you want to cut.If you know how wide or long you want the piece of foam you are cutting to be, you can use the measuring tape and marker to reference it later.Don't press down on the foam while you measure it, it will distort the size and shape.You should measure 2 or 3 times to make sure your measurement is accurate.
Step 3: Use a marker to mark the line.
Measure the point on the mattress with a long ruler or straight edge.Draw a straight line along the edge of the ruler with a marker.Depending on the shape and size of the piece you want to cut, you may need to draw multiple lines.Measure the distance from the ruler to the edge of the mattress to make sure the straight edge isn't slanted.The ruler is slanted if the distance isn't the same from both ends.You should draw a straight line from one end of the mattress foam to the other if you want to fit a smaller bed frame.If you don't want to cut a straight line, you can draw a curve on a large piece of paper, cut it out, and then trace it onto the mattress foam with a marker.You can either trace the curve on the paper or freehand it.
Step 4: The marked line doesn't have anything under the mattress foam.
Since you will be cutting through the foam with a knife, you don't want the line to be on a solid surface or you could end up chipping and scratching it.The space under the marked line can be opened by resting the foam on a stable surface.If you want the marked line to hang off the edge, you could rest the mattress foam on a table.If you want to cut a large mattress foam in half, try resting it on 2 box springs that have some space between them.The line in the center of the foam will sit over the open space.
Step 5: If you want a clean edge, use an electric carving knife.
You can use an electric carving knife to cut your mattress foam.You can get a cleaner, straighter edge when the knife is plugged in.If you don't have an electric carving knife, you can find one at your local department store or online.
Step 6: If you don't want to get an electric knife, try a regular one.
Although the cut may not be as clean and straight as it would be with an electric carving knife, a kitchen knife will also do the trick.If you plan on putting a new cover over your cut piece of mattress foam that will hide the edge, a kitchen knife is an easy, cheap option.If you're going to use a kitchen knife, make sure it has serrated edges.The longer the blade, the easier it will be to cut through foam.If you don't have a kitchen knife that will work, you may be able to use a pair of heavy-duty scissors if the mattress foam you're cutting is 8 inch (0.32 cm) or less thick.The cut may not be as clean as if you were using a knife.
Step 7: The knife should be held at a 90-degree angle.
It will be easier to cut into the foam.The line you marked on the foam should be lined up with the sharp edge of the knife.
Step 8: Cut along the marked line using an up-and-down motion.
If you are using an electric carving knife, you don't need to move the knife up and down since it will be moving on its own.Pull out the knife and separate the piece of foam at the end of the line.Make sure you follow along with the line so your edge is straight.You should cut along the line you marked if you are using scissors.
Step 9: If the knife doesn't go all the way through, repeat on the other side.
If you use a knife with a short blade, you may not be able to cut through your mattress foam.Measure and mark another line on the opposite side if that is the case.Cut through that line the same way you did on the other side, so that the foam separates into 2 pieces.Measure carefully to make sure the lines match up.
Step 10: Measure using measuring tape.
Measure from the edge of your mattress foam to the opposite side.You are all set if it is the right size.If you need to cut off more foam, you can repeat the process.If your measurement is too short, you won't be able to add foam back on.If you will be covering your mattress foam with a zip cover, you could try cutting a strip of foam that makes up the difference and placing it next to the larger piece inside the cover.
Step 11: Use a knife to smooth out jagged edges.
If your foam is going to be exposed, you may want to fix the edges if they are jagged.If you want to smooth out the edges, take a kitchen knife and cut off any jagged pieces that are sticking out.You might end up altering the size of the foam if you cut off too much.
Step 12: If you will be using a zip cover, put it over the foam.
If you don't want to alter or sew the old zip cover to fit your cut mattress foam, you can order a custom mattress cover online using the dimensions of your foam.Once you have a cover, you can put your mattress foam inside and then zip the cover up again.