How to Make a Bench Cushion: A Step-by-Step DIY Guide (and When to Go Custom)

Updated October 2026 · By Sam K, Fabrica Kraft

A bench without a cushion is a place to drop your bag. A bench with a good cushion is a place people actually sit: to pull on boots in the hallway, to read in the window, to squeeze one more person in at the dinner table.

Making your own bench cushion is a satisfying project, and this guide shows you exactly how. We'll also be honest about when it's easier to have one made, because we make a lot of them.

Quick answer: how do you make a bench cushion?

Measure the bench and cut a piece of foam to fit, usually 2 to 3 inches thick. Wrap it in polyester batting. Cut a top and bottom fabric panel, each 1/2 inch bigger than the foam on every side, plus a long side strip (called boxing) about 1/2 inch taller than the foam. Sew a zipper into the back section of the boxing, sew the boxing to the top and bottom panels, turn the cover right side out and slide the foam in. A first-timer should allow most of a day.

What you'll need

• Foam, cut to the size of the bench. High-density foam (1.8 lb per cubic foot or more) keeps its shape. For outdoor benches, use quick-drying open-cell foam.
• Polyester batting (often called Dacron) to wrap the foam
• Fabric: upholstery weight for indoors, solution-dyed outdoor fabric for verandahs and gardens
• A zipper, long enough to run across the back of the cushion
• Strong thread (outdoor thread for outdoor cushions)
• A sewing machine with a zipper foot
• Optional: piping cord, for a tailored edge
• Tape measure, fabric marker, pins or clips, sharp scissors, and an electric carving knife if you're cutting foam

Step 1: Measure the bench

Measure the length and depth of the seat where the cushion will sit. If the bench is built in between two walls, measure at the front and the back, because walls are rarely perfectly square. Use the smaller number.

Then pick a thickness:

A thicker cushion raises the seat. On a dining bench, that can leave people sitting higher than everyone on chairs, so measure the table height too. Our detailed guide on how to measure a bench cushion covers angled and notched benches.

Step 2: Cut and wrap the foam

Mark the size on the foam with a marker and straight edge. Cut with an electric carving knife, holding the blade straight up and down and using long, gentle strokes. Don't press hard, or the edge will be wavy.

Wrap the foam in batting, like wrapping a present, and hold it in place with a light mist of spray adhesive. Batting smooths out the cut edges and helps the cover look full instead of baggy.

Step 3: Work out your fabric

You'll cut three kinds of pieces:

• Top and bottom panels: foam length + 1/2 inch, by foam depth + 1/2 inch. Cut one, then use it as a pattern for the second.
• Boxing strip (the sides): foam thickness + 1/2 inch tall. It needs to run along the front and both short sides, plus about 8 inches extra so it wraps around the back corners.
• Zipper section (the back): two strips that together make the same height as the boxing, running across the back.

Example: for a 48 × 16 × 3 inch bench cushion, cut two panels of 48.5 × 16.5 inches and a boxing strip 3.5 inches tall and about 88 inches long, joined from shorter strips if needed. With standard 54-inch-wide upholstery fabric, that's about 1.5 to 2 yards once you add the zipper strips. Buy extra if your fabric has stripes or a pattern you need to line up.

Tip from Sailrite's cushion tutorial: if you have to join strips for the boxing, put the seams at the sides, not the front, so they don't show.

Step 4: Sew the cover

1. Make the zipper panel. Fold each back strip in half lengthways and sew one to each side of the zipper tape. Sew a small fabric stop at each end so the slider can't come off.
2. Join the zipper panel to the boxing strip to make one long loop that matches the outline of the cushion.
3. Add piping (optional). Sew piping around the edge of the top and bottom panels, starting at the back where the join won't show. Our cushion piping guide explains when it's worth it.
4. Attach the boxing to the top panel. Mark the center of each side on both pieces, line up the marks, pin or clip, and sew with a 1/4 inch seam. Clip into the boxing at the corners so it turns cleanly.
5. Open the zipper partway, then sew the boxing to the bottom panel the same way. (If you forget to open the zipper, you won't be able to turn the cover right side out.)
6. Turn it right side out and push the corners out with your fingers.

Step 5: Fill and finish

Fold the wrapped foam slightly, slide it into the cover, and let it open up inside. Line up the foam corners with the cover corners, smooth everything flat and zip it closed. If the cushion will sit on a slippery bench or outdoors in wind, sew fabric ties into the back seam so you can tie it to the bench legs or back.

Common mistakes to avoid

• Cutting the foam too small. The cover should be snug. A loose cover wrinkles and slides.
• Using low-density craft foam. It feels fine on day one and flat by month three.
• Indoor fabric outdoors. It fades and grows mildew fast. Use solution-dyed outdoor fabric outside.
• No zipper. Without one, you can never wash the cover or replace the foam.
• Ignoring the pattern. Stripes that don't line up between the top and the boxing are the first thing people notice.

DIY or custom: which makes sense?

If you'd rather skip the sewing, every Fabrica Kraft bench cushion is made to your measurements with no minimum order. Choose your foam and fabric, add piping if you like, and ties in matching fabric come as standard. Start with our bench cushions, or go straight to indoor bench cushions, bench and window seat cushions or piano bench cushions. Want to sew the cover yourself? We sell custom-cut foam on its own. Or keep your foam and order just a cover from custom cushion covers.

Not sure about a colour? Order fabric swatches and see them in your own light first.

FAQ

How thick should a bench cushion be?

Most bench cushions are 2 to 3 inches thick. Window seats often go to 3 or 4 inches for lounging. Dining benches are usually 2 inches so the seat isn't too high for the table.

Can I make a bench cushion without sewing?

Yes. Wrap foam and batting in fabric like a present and secure the underside with fabric glue or hook-and-loop tape. It won't be removable or washable, but it works for a low-use bench.

What foam is best for an outdoor bench cushion?

Quick-drying, open-cell foam, which lets rainwater drain straight through. Regular foam soaks up water and can grow mildew.

How much fabric do I need for a bench cushion?

For a typical 4-foot bench cushion about 16 inches deep and 3 inches thick, plan on about 1.5 to 2 yards of 54-inch-wide fabric, plus extra for patterns or piping.

Sources

• Sailrite: How to make an outdoor bench cushion with boxing
• Insider's Guide to Furniture: Sofa cushion density vs firmness