Guide
How to fix sagging couch cushions
Couch cushions sag when the foam core loses height and firmness with use, and the lasting fix is a new foam core cut to the size of the cover. The Polyurethane Foam Association (PFA) calls these losses compression set and flex fatigue, and reports that both are smaller in higher-density foam.
Foamera makes made-to-measure foam cushions and sells them online through TURKEX LLC.
Why do couch cushions sag?
Compression set is the permanent loss of height after foam has been compressed, and flex fatigue is the loss of firmness after foam is flexed many times. PFA reports that compression set decreases, and firmness loss is usually smaller, as density increases. A foam with a low support factor is also more likely to bottom out, so the cushion compresses down to the sofa base.
Which fixes work?
| Fix | What it changes | What it leaves as it is |
|---|---|---|
| Add a fiber wrap or batting | Softens the surface of the cushion | The support of the worn core underneath |
| Replace the foam core | New height and support from new foam | The cover, which you can keep if it is in good condition |
| Replace the whole cushion | New cover and new core | Nothing is reused |
What foam should the new core be?
PFA cites industry research that foams with a polymer density of 1.8 lb/ft³ (29 kg/m³) or higher perform better in seating, and notes that a support factor of 2.0 or above suits seat cushions. The best foam for couch cushions guide covers seat and back cushions.
How do I measure for a new cushion?
Measure the cover’s width, depth and thickness from seam to seam, and follow the measuring guide step by step.
Can Foamera make a new cushion for my sofa?
Yes: you enter the width, depth and thickness on the product page, choose High Density Foam or Fiber Fill, and choose the fabric. If you only need a new cover for a core you already have, choose Cover Only. To ask about a foam core without a cover, email hello@foamera.com.
How long will new foam last?
Foam life depends on density, use and care, and PFA reports that foam with a higher polymer density generally keeps its original properties longer.
Where can I order sofa cushions?
- Sofa and couch cushions
- Cushions for sectional sofas
- Bolster back cushions
- Kidney shape cushions
- Custom cushion cover with zipper (cover only)
- Foam density guide
Sources
- Polyurethane Foam Association, Foam Performance, Glossary and Furniture Case Study. Accessed 26 September 2026.
- Polyurethane Foam Association, IN•TOUCH Vol. 1 No. 2, The Importance of Density (revised 2016). Accessed 26 September 2026.
- Fill choices and extras: Foamera product pages.