All you need to cut upholstery foam is a serrated knife, preferably on the larger side. And I bet you already have one — a simple bread knife is perfect for the job! If you don’t already have one, this offset bread knife is perfect and only costs $11. Grab a marker and a measuring tape and draw a guideline for your cut on the upholstery foam.

Cutting curves can be challenging because the foam is more likely to compress and drag on the blade. Hold the blade as near upright as possible, and cut in small increments. Try to turn the blade gently as you go, following the curve. If you can maintain a continuous motion, you’ll end up with a smooth curve instead of a lot of small flats.

Trace the desired shape or curve onto the foam using a template or stencil. Plug in the electric knife and carefully plan how you will cut the foam as to avoid the cord getting in the way. Carefully follow the traced lines with the electric knife, allowing the blade to cut through the foam smoothly. Maintain a steady hand and consistent pressure.

Hot knives are user-friendly and accessible for beginners and professionals alike. A hot wire foam cutter features a heated wire that cuts through foam like a knife through butter. The wire is stretched taut between two points, allowing for precise, straight and curved cuts. It’s helpful for large-scale foam projects and intricate designs.