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9 Best Ways to Cut Styrofoam – Which Tool to Use?



If you are looking for the best way to cut Styrofoam, you will likely look for ways to do it artistically. Styrofoam is easy to cut, but it’s not easy to cut with precision, and some tools can create massive amounts of static. Whether you are looking to cut Styrofoam quickly or do it without making a mess, we’re going to look at various methods you can use to achieve your desired effect.

We checked with all our sources and found nine ways to cut Styrofoam. Join us while we look at each one and discuss the pros and cons.

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Styrofoam Cutting Methods

1. A Hot Knife – Preferred Method

RoMech Electric Hot Knife

The hot knife is our preferred method of cutting Styrofoam. It has the advantage over other knives because the heat seals the Styrofoam as it cuts. When you seal a cut, there’s less chance of creating the little Styrofoam beads that can often accompany cutting. The hot knife is also easy to control and position where you need it to make detailed cuts.

The downside to the hot knife is that there is the possibility of getting burned if you accidentally touch the heating element. You could also accidentally catch something on fire by inadvertently placing it on a flammable surface. It will require electricity, so you are somewhat limited to where you can use it, and you will need to seek out a brand that provides adequate heat and features you desire. If you purchased an inferior model, you might not have a good experience using it.


  • Cuts and seals
  • No mess
  • Easy to use
  • Possible burn danger
  • Requires electricity
  • At the mercy of the tool

2.  A Hot Wire Cutter

Hot Wire Foam Factory 2' X 4' Compound Bow Cutter

The hot wire cutter is very similar to the hot knife and has all the same pros and cons but is usually quite a bit larger. It can cut and seal the foam with no mess, and you can use it to create sculptures. Its large sizes are usually used in commercial applications to cut large sheets of Styrofoam.

The downside to the hot wire cutter is, once again, the potential for burns. These devices have a long wire that gets red hot and can easily burn you if you are not careful. It will also require electricity, and these devices are usually quite expensive.


  • Cuts and seals
  • No mess
  • Easy to use
  • Potential for burns
  • Requires electricity
  • Expensive

3. A Long Blade Utility Knife

Clear Style Store Utility Knife Heavy Duty Box Cutter

A long blade utility knife is the one you can snap off the blade as it gets dull to keep a sharp edge. This tool is perfect for cutting Styrofoam because the blade is both long and sharp, and it will stay in the open position while you use it. It’s inexpensive, readily available at most convenient stores, and allows for fairly intricate cutting.

The downside to the long blade utility knife is that it does not seal the Styrofoam as it cuts, which means there is a higher chance of creating tiny Styrofoam beads, and you might create a small amount of static while you are cutting. Unfortunately, the long blade utility knife is nowhere near as fast as the hot tools.


  • Long and sharp
  • Inexpensive
  • Can make detailed cuts
  • Slow
  • Doesn’t seal the Styrofoam
  • May create tiny beads
  • May create static

4. X-Acto Knife

X-Acto #1 Precision Knife

The X-Acto knife is very similar to a long blade utility knife but is not as long, and the blades do not snap off. It makes extremely detailed cuts and is for precision work where maximum control over the tool is required. With the X-Acto knife, you can create three-dimensional properties in Styrofoam.

The downside is the cutting blade is very small, so it’s only suitable for surface work. It also does not seal the foam as it cuts and can create static electricity.


  • Perfect for detailed work
  • Maximum control over cutting edge
  • Small cutting surface
  • Does not seal
  • May create static

5. Dental Floss

Reach Waxed Dental Floss

You may not believe it, but dental floss (waxed) can quickly cut through large blocks of Styrofoam, and many times, it makes less static electricity than metal tools. It’s also one of the least expensive solutions on this list.

The downside to dental floss is that it doesn’t seal the foam, so you still get tiny beads, and you can’t make accurate cuts like you can with the long blade utility knife or X-Acto.


  • Inexpensive
  • Quickly cuts large blocks
  • Less static
  • Doesn’t seal the foam
  • No accurate cuts

6. Guitar String

D'Addario EJ11-3D 80:20 Bronze Acoustic Guitar Strings

Guitar strings are very similar to dental floss and can be equally as effective at cutting through Styrofoam. The metal strings are more durable than floss and can handle more pressure. Some strings have another string around them, which creates a rough surface you can use to saw through the foam.

Unfortunately, guitar strings also do not seal the foam, and they are very limited in size compared to dental floss, which comes on a huge spool. When used to saw through the Styrofoam, guitar strings can create a huge amount of tiny foam particles and plenty of static electricity.


  • Faster and more durable than dental floss
  • Quickly cuts large blocks
  • You can use wound strings to saw through the foam
  • Sawing crates a huge mess
  • Doesn’t seal the foam
  • Limited size

7.  Cookie Cutter

Fox Run Star Shaped Cookie Cutter Set If you have a small amount of Styrofoam to cut up, you can use a cookie cutter to create tiny foam ornaments and decorations. These decorations are lightweight, and you can paint them any way you want.

The downside to cookie cutters is that it’s only suitable for a small amount of foam and is usually only considered viable for small projects.


  • Decorative
  • Creates a new project
  • Not practical for large jobs

8. Electric Knife

Hamilton Beach Electric Knife

If you have an electric knife like they sometimes use to cut Thanksgiving turkeys, you can use that to make short work of cutting through your Styrofoam. These devices have more than enough power to cut through foam even faster than the hot knife.

The downside to the electric knife is that there is no chance of using the foam for artistic purposes, and you’ll be finding tiny foam pellets for years after you use this tool.


  • Powerful
  • Fast
  • Not articulate
  • Messy

9. Cut Underwater

If your primary goal is to reduce mess when you cut the foam, you can try cutting underwater. The water will eliminate the static and capture the foam particles before they can escape into the air and your home.

Unfortunately, Styrofoam does not like to go underwater, so it will be a struggle to cut and often leads to a mess, but you don’t need to keep it submerged to receive the benefits.


  • Reduces or eliminates static
  • Captures foam particles
  • Can be messy

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Buyer’s Guide – The Best Ways to Cut Styrofoam

Let’s take a look at a few things you should consider before cutting Styrofoam.

What is Styrofoam?

Styrofoam is petroleum-based polystyrene and about 95% air. It’s extremely lightweight yet rigid enough to form cups and food containers, and has many other uses as well. Though it’s very useful, it’s bad for the environment and contains several ingredients that can harm your health, especially when you cut it.

Eyes, Lung, and Skin Irritation

The dust created when cutting Styrofoam with a dry tool can irritate the eyes, lungs, and skin. Many people develop itchy skin from continuous exposure, but there are also reports that some people develop difficulty breathing.

Nervous System Damage

Heating and burning can release harmful chemicals into the air. Some of the substances include aromatic hydrocarbons, styrene, ethylbenzene, hydrogen bromide, chloride, and fluoride. Some of these chemicals can affect the nervous system and manifest in several symptoms including headaches, fatigue, weakness, and even depression.

May Cause Cancer

Besides affecting the nervous system, some of the chemicals released into the air may have cancer-causing properties. Particularly dangerous are hydrocarbons, benzene, and styrene.

Safety Equipment

If you need to cut Styrofoam, we highly recommend choosing a location with plenty of ventilation. You may even decide to use an exhaust system or a portable fan to direct dust and harmful gases away from your position, but there are a few more things you should purchase as well.

Safety Glasses

While Styrofoam is a soft material, the dust is an irritant. If the dust is airborne, it can get into the eyes and irritate them. Safety goggles with side protection can help to keep the dust out of your eyes while you work.

Dust Mask

A dust mask is essential when cutting Styrofoam. Whether you are using a hot knife or dry cutting, you will need to cover your nose and mouth to improve the air quality going into your lungs. We recommend a high-end mask to help reduce the risks presented by both dust and fumes.


The final piece of safety gear that you should wear while cutting Styrofoam is heavy-duty work gloves. These gloves will protect your hands from cuts and burns while you work, and they will also help protect your skin from becoming irritated by the dust created.

Related Read: How to Cut Retaining Wall Blocks in 5 Simple Steps

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As you can see, there are several ways to cut Styrofoam at your disposal. If you have a small amount of Styrofoam you need to cut up, we recommend the long blade utility knife or submerging it in water. If you have a large amount of foam to cut up quickly, we recommend the electric knife. If you need to cut foam regularly, we recommend the hot knife or hot wire cutter.

We hope you have enjoyed reading over this guide and have found the answers you came to get. If you have found it informative, please share these nine best ways to cut Styrofoam on Facebook and Twitter.


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