Making a foam bed smaller is a handy skill. You might be fitting a mattress into an RV, a bunk or a small bedroom. You can also reuse pieces for couch cushions or dog bedssleepline.com. This guide shows you how to cut foam safely.

Why people cut foam or memory foam mattresses

To fit a mattress into a smaller frame or tight spacesleepline.com.
To split a large mattress into two smaller piecessleepline.com.
To make seat cushions or pads from extra foamsleepline.com.

If your foam has gel beads, know that cutting may disturb the cooling layerpuffy.com.

Tools and safety gear

Gather the right tools before you begin:

Measuring tape and marker. Measure twice and mark straight lines on the foamwasteremovalusa.com.
Straight edge or ruler. Use it to guide your cutswasteremovalusa.com.
Serrated bread knife or electric carving knife. These make clean cuts in foampuffy.com.
Heavy‑duty scissors or utility knife. Keep spare blades; dull blades tear foamwasteremovalusa.com.
Gloves, goggles and a mask. They protect your hands, eyes and lungswasteremovalusa.com.
A flat, stable surface. Work on a table or sawhorses so the mattress stays stillamerisleep.com.

Safety matters. Wear long sleeves and closed‑toe shoesamerisleep.com. Work in a well‑ventilated space to avoid breathing foam dustwasteremovalusa.com. Keep kids and pets away from the areaamerisleep.com.

Step‑by‑step: measure, mark and cut

Measure and mark. Decide the size you need. Use the tape to measure and mark the cut linepuffy.com. Draw the line with chalk or a washable marker.
Lay the mattress flat. Place it on your work table. Ask a friend to hold it steadypuffy.com.
Cut along the line. Use a serrated knife or electric knife. Guide the tool gently; let the blade do the workpuffy.com. Do not press down hard or bend the foamwasteremovalusa.com.
Check your progress. Stop every few inches to make sure you are staying on the line.
Smooth the edge. After cutting, use sandpaper or a sharp blade to trim rough spotspuffy.com.

Take your time. Rushing can cause jagged edges or uneven cutspuffy.com.

Smooth edges and clean up

After the cut is complete, tidy the area:

Trim any rough bits with scissors or sandpaperwasteremovalusa.com.
Collect foam scraps and fabric pieces. Place them in bags so they don’t scatterwasteremovalusa.com.
Use a small vacuum or hand broom to remove dust and bitswasteremovalusa.com.

Reuse and dispose of leftover foam

Foam and metal pieces should not go to the landfill when they can be reused or recycled:

Use leftover foam to make bench cushions, pet beds or craft projectswasteremovalusa.com.
Remove any metal springs and take them to a scrap recyclerwasteremovalusa.com.
Check local rules for foam recyclingwasteremovalusa.com. Many communities have drop‑off sites.
Donate foam pieces in good condition to shelters or schools.

Tools & safety box

Wear heavy‑duty gloves and goggleswasteremovalusa.com.
Put on a mask if the foam contains fiberglass or chemicalswasteremovalusa.com.
Work in a bright, airy spaceamerisleep.com.
Keep a first‑aid kit nearby for minor cutsamerisleep.com.
Practise on a spare piece of foam before cutting the mattresspuffy.com.

Frequently asked questions

Can you cut a gel memory foam mattress? Yes. You can cut gel foam like regular foam, but the gel beads may not spread evenly after cuttingpuffy.com.

Does cutting memory foam void the warranty? Many makers void the warranty if you alter the mattresspuffy.com. Read the tag or call the company.

What is the best tool to cut memory foam? A serrated bread knife or electric carving knife makes clean cutspuffy.com. Sharp blades are safer than dull oneswasteremovalusa.com.

How do I smooth the edges? Lightly sand or trim the cut edge until it feels evenpuffy.com.

Keep exploring mattress cutting tips

Cutting a mattress is just one part of the story. Explore these related guides to take your project further:

Find the right tool for the job – learn which heavy-duty cutters make quick work of metal coils and see how to use them safely in our guide to the best tool to cut mattress springs.
Stay safe when dealing with springs – if your mattress has coils, follow our step-by-step instructions on how to cut mattress springs safely to prevent injuries and handle disposal responsibly.
Brand-specific considerations – wonder if your high-end bed can be resized? Our article on whether you can cut a Tempur-Pedic mattress explains warranty issues, tools and safer alternatives.
Breaking down a full mattress – for disposal or repurposing, our guide to cutting up a foam mattress shows how to dismantle layers, sort materials and recycle them wisely.

These resources build on what you’ve learned here and ensure you have all the knowledge you need for a smooth, safe mattress-cutting experience.