I need to cut 2x2 ft square pieces from a sheet of memory foam. Not sure what tool is best for this. Any ideas? In the future I'd like to cut circles and eventually sculpt irregular shapes, I don't know what tool can be used for this sort of job.


10 Answers 10


For thicker pieces you might find you get better results by compressing the foam before cutting it. You could make a simple straight-line clamp out of a couple of 2x4s linked with a door hinge -- just put your foam in between, clamp the open end shut with a C-clamp, and use one edge of the wood as a guide for your cut. For your curved cuts it might make more sense to make a plywood die to match the final shape and press it down by hand or with something heavy before cutting around it.

  • 3
    Compressing first makes a ton of sense. I used to run a blinds franchise and had to cut honeycomb shades occasionally. Compressing then cutting resulted in near factory edges.
    – Evil Elf
    Commented Aug 16, 2011 at 14:23
  • Thanks -- using this trick for honeycomb shades is an awesome idea too! Commented Aug 16, 2011 at 21:48
  • It is hard to visualize, could some one post a picture of how the setup looks like?
    – haridsv
    Commented Oct 1, 2011 at 18:06

I used a sharp razor knife on my memory foam. You can make a line and just make long cuts. Do not try to cut through it all at once. Start by making your first cut deep enough that you can follow it through and make a straight cut. Just keep cutting down your line until you are through. Take your time and be careful and you will have a clean cut. Don't use a saw or hot knife you will just ruin your topper.

A razor knife is your best tool for this.

  • 2
    I was afraid this was the answer. It's what I do too, but it requires a steady hand and a ton of patience. I've yet to make a cut I was remotely pleased with. Commented Aug 16, 2011 at 12:12
  • If you wanted, you could make you a mark with a chalkline or some straight edge to go by. Mine was not perfect either. But the sheets will cover it :). If you do not want to sell it the future, dont worry about it being too messy. It will still work the same.
    – lazoDev
    Commented Aug 16, 2011 at 17:30
  • Sharp Chef's knife works as well: en.wikipedia.org/wiki/Chef's_knife The added width of the knife helps keep the cut from wandering as you get deeper into the foam. Commented Jan 16, 2016 at 18:15

An electric fillet knife does great at cutting this stuff. Seriously. Give it a try if you have one.

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    Agreed (and I'm guessing so does Yitchak, who might not've realized they go by more than one name). It's that strange electrical appliance that you'd see in the 1970s for carving turkeys or roast.
    – Joe
    Commented Aug 29, 2011 at 20:39
  • I've used an electric carving knife for cutting memory foam and it worked very very well.
    – Haendler
    Commented Oct 28, 2017 at 1:42

If this were styrofoam, I'd recommend a hot knife (basically a wire stretched taut on a frame similar to a jigsaw, and electrified to heat it). However, visco-elastic foam will behave differently and you probably don't want to be breathing in the fumes produces by melting it.

In this white paper from the Polyurethane Foam Association regarding visco-elastic ("memory") foam, the PFA states that most conventional tools including saws can be used to cut VEF. However, care must be taken to go slowly and not deform the foam too much with the cutting action, because the slower recovery of VEF to its original shape will cause defects in the kerf line and possibly cause the saw to bind more easily.


I use an electric carving knife. It works great.


If you don't have an electric carving knife, which is the best tool, use a serrated bread knife. Same action on both.

  • This worked for me as well, its quite controllable if you use a l right sawing motion Commented Jun 27, 2018 at 8:58

a really sharp knife should do the trick.


I strongly recommend you let the mattress chill outside on a flat surface that maintains its original shape. The mattress becomes very hard when cold, in the same way warmth causes it to soften.

I would then follow the PFA recommendation; "that most conventional tools including saws can be used to cut VEF".

P.S. I do not know what the PFA thinks about having soft or hard memory foam, but I know which of these I prefer.

  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. Commented Dec 9, 2019 at 17:21

I used a pair of Cutco scissors. They worked great. The foam I cut was about 3" thick. I tried some other scissors first but they didn't even think about cutting it. I think the reason the Cutco scissors worked so well is the serrated edge they have. This made them bite into it instead of pushing back out like the other scissors I tried to use.


Well the best option is to clamp the memory foam between the 2 x 4' s.mentioned before.on top off a sharpy marked line, which is a marker.adjustable wood working clamps would work great for this. no matter how thick, which will decide the length of your knife. a good brand new razor utility knife preferably one that is disposable the kind that when you extend it you can break off the used dull portion. By using this kind of . razor knife when new you can extend it long enough to make a deep good clean cut through the thickness. without having to buy or use one of your wife's or husbands kitchen knives or just something that just won't do a good job Wright off the bat, and wind up with something that looks like A person having a nervous break down did it . the cost of a new razor knife like this is at the most $5 bucks at the dollar General store.

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