How To Cut Styrofoam In Less Than 5 Minutes

Styrofoam is one of the most versatile materials on the face of the earth. Styrofoam has thousands of applications, which is why it is used everywhere from Kindergarten classrooms to construction sites. While Styrofoam is great the mess it makes can be a pretty big detractor. It also has a much higher likelihood of falling apart when trying to shape it compared to wood or metal. This causes most people to throw Styrofoam away as soon as they get it. This is a shame because there are a lot of different craft projects that Styrofoam is great for. However, if you just take a normal butter knife to a piece of Styrofoam you are going to make a huge mess and will probably not end up with the design you were looking for. In this article we have broken down the easiest ways to cut Styrofoam no matter what your needs. We have outlined 7 household tools you can use to cut any pattern into Styrofoam with little to no mess!

What is Styrofoam?

Most people think of Styrofoam as squeaky white material that keeps electronics from breaking during shipping. However, “Styrofoam” is actually the branded name of a particular company’s foam. Think of it like Kleenex compared to facial tissue. Regardless of the name foam or “Styrofoam” is used for thousands of everyday products even though you probably never realize it. This includes plates, bowls, insulation, surfboards, and much more. The main “ingredient” of Styrofoam or any other foam boards is petroleum. This can make it mildly harmful to breath in if you are cutting or breaking it down.

Cutting Manually (The Simplest Method)

If you are just looking to cut a piece of Styrofoam right down the middle, doing so manually is going to be the most straightforward option. Cutting styrofoam manually is typically the most cost effective and easiest option for basic cuts. Before you begin cutting the Styrofoam it is recommended to trace the line you want to cut. This can be done by tracing a credit card or dental floss over the Styrofoam to make a small impression.  Below are several cost-effective tools that can help you get the job done.

Tool #1 Hot Knife

hot-knifeA hot knife is our top choice for cutting Styrofoam. A heated knife is ideal for making small cuts and leaves minimal mess compared to a normal serrated knife. The key is to use a sawing motion when cutting instead of pushing straight down. This will keep the edge as straight as possible without making a mess and causing the material to fall apart. If using a regular knife holding it over a candle for 10-15 seconds will greatly improve the straightness of the knife. The heated blade also works perfectly for making cuts at different angles.

Tool #2 Dental Floss

This may seem like a silly option but it works great in a pinch. Dental floss is perfect for cutting through soft materials like Styrofoam. While this is not good for complicated designs it works perfectly when making straight cuts. It is best to trace a line with a credit card, ruler, or pencil before making the cut with dental floss. This ensures when you pull the floss down it will cut in a straight line. The best motion to use is to lay the Styrofoam on top of the dental floss. Then place one hand on top of the Styrofoam and pull the dental floss towards you with the other hand. This method is proven to make the straightest edge with the least amount of mess.

Tool #3 X-Acto Knife

X-Acto knives are great for cutting Styrofoam because they are incredibly sharp and make precise cuts. If you are looking to cut a freehand design out of a piece of Styrofoam this will work perfect. In fact they are so sharp the eliminate the need for a heated blade. However, they do not work well for large pieces of Styrofoam. This is because X-Acto knives do not have long blades. This can make cutting thick pieces of Styrofoam extremely tedious and messy if you need to keep retracing the same cut.

Tool #4 Hot Wire Cutter

Hot wire cutters are great for cutting Styrofoam if you already have one. However, because a decent hot wire cutter usually runs around $100 buying one just to cut Styrofoam probably is not the wisest use of funds. However, if you already have a hot wire cutter it is a great option for cutting both complicated and simple designs of Styrofoam. Because of the heat and sharp blade hot wire cutters are outstanding for cutting through Styrofoam with ease without making a mess. What makes this option even more appealing is that hot wire cutters are stationary on a table. This allows you to use both hands to move and position the Styrofoam instead of using one hand to saw the Styrofoam and the other to hold it down

Tool #5 Electric Knife

An electric knife is a great option for cutting through multiple pieces of Styrofoam at once (or one extremely thick piece of Styrofoam). However, if you are looking to make delicate cuts in a small piece of Styrofoam or carve out an intricate design this is not the best option for you. Electric knife also tend to make a bit more mess than hot knives or dental floss. However, they cut straight and can tear through large pieces in seconds with virtually no effort required.

Tool #6 Foam Cutting Saw

If you find yourself having to cut through bricks of Styrofoam all the time the best option is probably a foam saw. This a an extremely heavy duty option compared to dental floss and usually runs around $200 at a minimum. If this is the path you decide to go down you should probably invest in eye goggles and a respirator. Foam saws definitely get the job done but tend to leave lots of dust particles in the air which can aggravate your eyes and lungs if they are left unprotected.

Tool #7 Cookie Cutters

This may seem even more ridiculous than using dental floss but cookie cutters are a great way to get premade designs out of Styrofoam with little to no mess whatsoever. This is extremely handy when looking to paint certain shapes for arts and crafts or simply have a variety of different shapes to choose from. Use a cookie cutter for Styrofoam the same way you would for cookie dough. Just press it down and you are good to go.

Other Notes

If using a freehand knife cutting Styrofoam underwater will greatly reduce the mess. Styrofoam is actually waterproof so keeping it underwater for a minute or two will not damage the materials.


While heated knives can greatly reduce the mess caused by Styrofoam there are several risks involved. Some types of Styrofoam will release “off gassing chemicals” when heated. Essentially this means tiny particulates are released into the air when heated. Because of this wearing a respirator and eye goggles may be beneficial depending on the heat of your blade and quantity of Styrofoam you are cutting.

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