Easy to sew box cushions


New Member
Apr 14, 2022
Our trailer was purchased as a project and had 0 upholstery and only 1 torn up mattress.

After asking on here for replacement suggestions and the same on Facebook we ultimately decided to try and make new ones.

I am not a expert seamstress but I can sew and have a sewing machine. If you've never used a machine before this will not be a project for you.

Here is how I did it.

10 yards of 54" wide outdoor fabric ($7 a yard on sale)
1 spool of outdoor upholstery thread ($2)
1 queen size 4" mattress topper 2"HD foam/2"Memory Foam ($150)

Total cost for dinette AND long bench box cushions = $222 about the same as just the dinette replacement on Amazon.

We cut the mattress topper with a electric carving knife to measurements for the foam base.

On the reverse side of the fabric trace around your foam 2x for each cushion.

Then on one of your pieces of fabric extend your lines out the depth of your foam - .25" (I had 4" foam so for mine it was 3.75")

Connect those lines so you have a box within a box drawn on the reverse of the fabric
Cut along the outside lines for your box within a box and on the line of the foam sized box.

Cut out the squares in the corners of the box within a box piece.

Sew the corns together so you have 1 piece of fabric that is the top/sides of your cushion.

Sew a zipper zip facing away from you on the reverse in the middle of the foam sized piece of fabric. Then cut away the fabric to reveal your zipper.

Sew top side to top side the foam sized piece to the 3 sided piece. Don't worry about the lack of seam allowance trust me it will be ok.

Unzip and turn the cover right side out then put around your foam.



  • IMG_20221002_124536_01.jpg
    183.5 KB · Views: 18
  • IMG_20221002_124131_01.jpg
    156.9 KB · Views: 18
  • PXL_20221002_215604495~2.jpg
    199.2 KB · Views: 16
Last edited: