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Best Way to Cut Foam Board – Which Tool to Use? – Reviews & Buyer’s Guide

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a tool for cutting foam board

Whether you’re using foam board as insulation, for building material, photography mounting, or crafting, you probably want to know how to cut it cleanly and quickly. You want to get through the foam with ease, but you also don’t want to leave a ragged edge, and you definitely don’t want to create toxic fumes in the process. But there are just as many ways to cut foam as there are types of foam, so we’ve created this review-packed guide to help you sort out the various methods and tools that will get the job done. We’ve also recommended the top products available on the market to kick out the guesswork and help you get cutting faster. Read on to learn about our top 5 picks that will help you decide where to start.

Comparison of our Favorite Picks for 2020

RankModelOur Favorite Product
#1A Long Bladed Utility Knife
Slice 10559 3″ Extra Long Industrial KnifeOur Preferred Way
Slice 10559 3″ Extra Long Industrial Knife

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#2A Hot Knife
RoMech Foam Cutter – Pro Electric Hot Knife (200W)
RoMech Foam Cutter – Pro Electric Hot Knife (200W)

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#3An X-Acto Knife
Xacto X5282 Basic Knife Set
Xacto X5282 Basic Knife Set

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#4A Hot Wire Cutter
Hercules Tabletop Styrofoam Hot Wire Cutter (CT-115)
Hercules Tabletop Styrofoam Hot Wire Cutter (CT-115)

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#5A Foam Cutting Saw
Acu-Cutter 350 Foam Saw w/ 8″ Blade
Acu-Cutter 350 Foam Saw w/ 8″ Blade

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The 5 Best Tools for Cutting Foam Board

1. Long Bladed Utility Knife – Our Preferred Way

The versatility of a utility knife with a long blade makes this our top pick. You can use it for most thicknesses of foam, including for crafting or foam board insulation. Make sure you choose a smooth blade, though (not serrated), to avoid those ragged edges. You’ll want to apply some weight to the foam board to keep it from sliding (turn foam board insulation flat side up) and cut in one smooth motion at about a 45-degree angle. If you start sawing at the board, you’ll end up with ugly edges and little foam shreds flying everywhere. Check out our pick below for a good-quality utility knife that will get your job done quickly.

We recommend the Slice 10559 3″ Extra Long Industrial Knife:

Slice 10559 3' Extra Long Insulation Foam Tool,...
45 Customer Reviews
Slice 10559 3" Extra Long Insulation Foam Tool,...
  • Slice safety blades' unique cutting edge might seem dull, but it cuts right through your material...
  • Safe and effective sharpness and stay there 11 times longer than steel.
  • 4 Preset Cutting depths, handle a variety of materials. Extra long tool stops are specially designed...
  • Smooth blade
  • Adjustable cutting depth
  • Easy change blade
  • Versatile for different thicknesses of foam
  • Economical
  • Requires some manual strength/grip
  • Knife not ideal for harder surfaces

2. A Hot Knife

When a standard knife won’t cut it, you might need some power. A hot knife can give you power along with freedom of movement, which makes it our second pick. Like the long-blade utility knife, it’s also great for varying thicknesses of foam. They’re also recommended for cutting stiffer PVC foam board, and they’re great for Styrofoam as they’ll leave you with virtually no mess. As with any heating element against foam, check the manufacturer recommendations, as some foam types can off-gas toxic chemicals. If this is the case, you can always wear a mask and goggles before cutting. Check out our top pick from the hot knife market below. It will get you cutting through foam with ease.

We recommend the RoMech Foam Cutter – Pro Electric Hot Knife (200W):

RoMech Foam Cutter - Pro Electric Hot Knife (200W)...
202 Customer Reviews
RoMech Foam Cutter - Pro Electric Hot Knife (200W)...
  • ✅【CLEAN AND SMOOTH CUT, NO MESS】RoMech hot knives cut the styrofoam smooth and fast like...
  • ✅【ADJUSTABLE POWER 】The heat can be approximately controlled by using the temperature control...
  • ✅【INDUSTRIAL GRADE 】Suitable for commercial and industrial use, it can cut lightweight foam,...
  • Mess free
  • Easy to handle
  • Heavy duty for personal or industrial use
  • Need a handy power source where you’re cutting

3. X-Acto Knife

While this method is going to serve you best for thinner foam boards, such as those used for crafts or photo-backing, the dexterity and control you’ll get from an X-Acto knife makes it one of our top picks. Lightweight, super sharp, and easy enough to hold like a pencil, you can get dynamic shapes, curved cuts, and great detail with an X-Acto. On the downside, you won’t want to rely on one of these for thicker foam, especially the type of foam board used in construction. The amount of effort and pressure you’ll need will give you nothing but a headache. Stick with an X-Acto for foam thicknesses less than 1 inch. As with the long blade utility knife, you’ll want to cut in a smooth motion without sawing to keep your edges clean. Check out the set below, which includes multiple interchangeable blades to give you versatility in your projects.

We recommend the Xacto X5282 Basic Knife Set:

X-ACTO Basic Knife Set | Set Contains 3 Precision...
1,755 Customer Reviews
X-ACTO Basic Knife Set | Set Contains 3 Precision...
  • Xacto basic knife set for lightweight precision cutting
  • Ideal for cutting wood, cardboard, paper, plastic, cloth and foam board
  • Craft
  • Interchangeable blades
  • Top crafting knife on the market
  • Excellent sharpness
  • Economical
  • Poor performance on thicker foam
  • Container isn’t great

4. Hot Wire Cutter

Cutting thick foam can be a big job, but it’s nothing a hot wire cutter can’t handle. Designed to slide effortlessly through foam and leave perfect edges, these cutters can provide diversity in the way you cut. They’re great for crafts and intricate cutting, as well. While you’ll need to use extra caution with fumes (check the foam manufacturer for recommendations on heating it) and be careful with the heat, you can save yourself a lot of effort by using this method. They come in different styles, too. The first is a tabletop model with a square and measuring ticks (which we recommend), and the second is a handheld device that comes in either a wand style or an arc. For ease of use, a tabletop device is perfect. Check out our top pick below.

We recommend the Hercules Tabletop Styrofoam Hot Wire Cutter (CT-115):

Hercules Tabletop Styrofoam Hot Wire Cutter...
30 Customer Reviews
Hercules Tabletop Styrofoam Hot Wire Cutter...
  • 💪 The Hercules CT-115 Hot Wire Foam Cutting Table heats up quickly; the wire can reach its...
  • 💪 The Hercules CT-115 cuts quickly and smoothly; it seals the edges clean without leaving debris.
  • 💪 Easily cuts shapes like cylinders, cones, tapers, cubes and polygons by simply adjusting the...
  • Heats quickly
  • Variation of shapes
  • Good stability
  • Good midrange price point
  • Not good for big sheets.
  • Not for industrial use

5. Foam Cutting Saw

On the opposite side of the spectrum from the X-Acto knife is a foam cutting saw. If you need to cut large amounts of thick foam, an electric foam saw will spare you countless hours of manual labor and grip fatigue. Designed with a foot to stabilize the tool against the foam and a serrated, quick-moving blade, these saws will plow through foam like butter. Because of the quick, powered blade movement, you’ll also end up with smooth edges. On the downside, it could leave a mess of foam particles in your work area. They’re also on the higher end of the price spectrum. Check out our top pick below for the best electric foam saw of 2020.

We recommend the Acu-Cutter 350 Foam Saw w/ 8″ Blade:

Acu-Cutter 350 Foam Saw w/ 8' Blade
12 Customer Reviews
Acu-Cutter 350 Foam Saw w/ 8" Blade
  • Volts: 120 AC, Amps: 4.5
  • Variable Speed, 0-3200 RPM
  • Includes 8" blade (1 stationary, 1 reciprocating) and base
  • Great for thick foam
  • Perfect for large projects
  • Works for textile foam
  • Contact company for blade replacement
  • High price point

Buyer’s Guide

While you have many options for cutting foam, the best option is almost always the simplest. A long-bladed utility knife will perform perfectly under most conditions, and they’re versatile enough that you can use them for other materials, as well. If you have a big project, consider a power tool such as the hot knife to give your hands a break. You’ll still get beautifully clean edges efficiently and quickly. No matter what you choose, be sure to steer away from anything with teeth or that requires a sawing motion, as you’ll ruin your edges and leave a mess of foam shreds in your workspace. But the great thing about foam is its softness and pliability, making it easy to work with. You can purchase an inexpensive tool and still have great success.

More pages like this one:

-> What’s our preferred way to cut plaster?

-> Which tool do we recommend you use for cutting metal roofing?


We hope these product reviews have helped you decide on the best tool and method for your needs. Remember to keep it simple for the best results. If your job is a big one, go for some heat. If you’re crafting or using thin sheets, go for small and sharp. Smooth strokes will get you clean cuts, and you’ll want to avoid serration unless you want to clean up the mess afterward. Good luck finding the perfect product. Now go tackle that foam!

About the Author Ryan Doskocil

Ryan is a freelance writer from Arizona. When he's not blogging about his favorite hobbies, he's writing fiction, hiking or running in the great outdoors, and spending time with family.