upholstery foam 18x120

If you're building a long bench, window seat or booth, upholstery foam 18x120 saves you from piecing together short slabs. An 18 x 120 foam sheet gives you one continuous run of cushioning, about ten feet long, that you can trim to size for a clean, seamless seat.

Why Choose a Long Foam Sheet

A single long foam sheet avoids the visible joints and uneven dips that appear when smaller pieces shift under use. It's a smart pick for banquette cushion foam, porch swings, mudroom benches and RV or boat dinettes where seating stretches wall to wall.

What to Look For

Thickness

Thinner foam works well for back pads and padded headboards. Thicker bench cushion foam suits seats that see everyday use.

Density and Firmness

High density upholstery foam generally holds its shape longer and resists sagging. Match firmness to how the seat will be used: firmer for dining benches, softer for lounging and window seat foam.

Indoor or Outdoor Use

For patio, porch or marine projects, look for foam made to drain and dry quickly so moisture doesn't linger inside the cushion.

Shop Our 18x120 Foam

Browse the foam options below, compare thickness and firmness, and pair your choice with a durable upholstery fabric to finish your project.