None of the sizes seem to fit my cushion?

Answer:

This is a DIY solution where you determine and control how much thickness support you need and then customize for the size you need.  Because this inserts inside your cushion cover to compress your remaining foam density, the possibilities are endless to fit larger or smaller cushions. It makes no difference if that is accomplished with one. two or three pieces. Some people want to cover their entire cushion while others focus the support only in the area of the cushion they actually sit on.

You can cut-to-fit these inserts as needed – or even order an extra insert and use the extra material to fill in for your particular cushion’s width or length. You can cut with a straight edge and a utility knife, good scissors or power tools. You measure and you control how thick and how big you want your insert to be.