---
title: "Floor Sofa Foam Density: 28-Density Seats, About 1.75 lb/ft³"
url: "https://cushionguide.com/answers/floor-sofa-foam-density/"
section: "The Cutting Table"
author: "Nate Kowalski, The Pattern Engineer of Detroit"
author_url: "https://cushionguide.com/masters/nate/"
published: "2026-02-18"
updated: "2026-09-24"
keywords: "floor sofa foam density, 28 density foam, modular sofa foam, high density foam floor couch, floor sofa replacement foam"
---

# What density foam is inside a floor sofa?

*Everyone asks whether a floor sofa is comfortable. The sharper question is which number sits inside it. Here is the number, and five lines to ask any seller.*

Also asked as: what is the foam density; what kind of foam is in the couch

> **The quick answer:** Floor sofa seat mattresses use 28-density high-density foam, about 1.75 lb/ft³ (28 kg/m³): a medium-hard flexi foam that stays comfortable and lasts for years without collapsing. Some replies quote it as 28 to 32 density, and one corduroy sofa was given as 32. The backrests are foam-filled too, and replacement foam is sold on its own.

![Rust orange and cream velvet floor sofa on a jute rug, with pampas on a rattan table, wicker baskets and stacked books](https://cushionguide.com/media/modular-floor-sofas/rust-cream-floor-sofa-boho-corner-rattan-table-1600.webp "Rust velvet ends pick up the jute rug, rattan table and baskets around this floor-level sofa.")

## Key facts

- Seat foam: 28 density, about 1.75 lb/ft³ (28 kg/m³).
- Described as medium-hard, high-density flexi foam; one reply added a 42 ILD firmness.
- Some replies quote 28 to 32 density; one corduroy sofa was given as 32, about 2.0 lb/ft³ (32 kg/m³).
- Built to last for years without collapsing.
- Backrests are foam-filled.
- Standard covers are 100% polyester corduroy, in fabrics from a mill certified to OEKO-TEX Standard 100 (03.T.3239).
- Replacement foam is sold on its own.

## Five things to ask any floor sofa seller

1. **Seat density.** Here: 28, about 1.75 lb/ft³ (28 kg/m³). Cheaper look-alikes often save money on low-density foam.
2. **Firmness.** Density is not firmness. This seat is medium-hard; one reply put it at 42 [ILD](https://cushionguide.com/glossary/#ild).
3. **Backrest fill.** Foam-filled here; copies often use solid foam blocks.
4. **Cover fabric.** 100% polyester corduroy as standard, from [OEKO-TEX Standard 100](https://cushionguide.com/guides/oeko-tex-standard-100-cushions/) certified mills.
5. **Replacement foam.** Ask if it is sold alone. Here it is, so a tired seat does not mean a new sofa.

## 28 or 32: why you'll see two numbers

The usual answer is 28 DNS. Sometimes it's given as 28 to 32, and a corduroy sofa was once quoted at 32. I read that the way I read any spec sheet, partner: 28 is the stated number, 32 the top of the band. If the exact figure matters, ask for it on your order. What number did the last listing you looked at give?

To convert, divide kg/m³ by 16.02. The [density conversion table](https://cushionguide.com/guides/foam-density-lb-ft3-kg-m3/) has the rest, and [how long foam lasts](https://cushionguide.com/guides/how-long-does-cushion-foam-last/) covers what density means for the years ahead.

## When a seat finally tires

Replacement foam is sold without covers: full sofa foam sets, with the metal supports if you need them, quoted per set through a dedicated link. Pillow fillings and foam-only backrest inserts go the same way; see [foam inserts](https://cushionguide.com/cushions/foam-inserts/).

> **Tailor's margin:** Floor sofa foam at 28 density weighs about 1.75 lb per cubic foot (28 kg/m³). Ask a seller for that number, not just the word soft or firm.

> A floor sofa seat on 28-density foam, about 1.75 lb/ft³, is medium-hard and built to last years. Cheaper look-alikes save money on low-density foam and solid backrests.
>
> — Nate

## Buyer questions

**A common question:** What foam density do you use in the modular sofa?

**The workshop's answer:** The seats use 28-density high-density foam with a 42 ILD firmness, and the backrests are foam filled. Cheaper look-alikes often use low-density foam and solid-foam backrests.

**A common question:** What density is the seat foam in the teddy floor sofa?

**The workshop's answer:** Medium-hard, high-density flexi foam rated 28 density (28 DNS), under corduroy outer covers.

**A common question:** What is inside the cushions, and will they flatten?

**The workshop's answer:** Medium-hard foam at 28 density, sometimes quoted as 28 to 32. It is meant to last many years, and replacement foam is sold on its own.

**A common question:** What foam and fabric are your sofas made of?

**The workshop's answer:** In that reply, 32-density high-density foam that won't collapse over time, under 100% polyester corduroy chosen for its soft feel and wear resistance, in fabrics from a mill certified to OEKO-TEX Standard 100 (03.T.3239).

## Questions buyers ask next

### How do I convert foam density from kg/m³ to lb/ft³?

Divide by 16.02. So 28 kg/m³ is about 1.75 lb/ft³ and 32 kg/m³ is about 2.0 lb/ft³. Density is weight for volume; firmness is a separate measurement, usually given as ILD.

### Is 28-density foam dense enough for a sofa used every day?

In these floor sofas, yes. It is a high-density, medium-hard foam that the workshop says lasts for years without collapsing. Bench cushions from the same workshop use a firmer 32 density.

### Can I buy just the foam for a floor sofa, without covers?

Yes. Foam is sold on its own, from pillow fillings and foam-only backrest inserts to full sofa foam sets with the metal supports if needed, quoted per set through a dedicated link.

## Related at the atelier

- [Is the floor sofa cold foam or regular high-density foam?](https://cushionguide.com/answers/cold-foam-vs-high-density-foam-floor-sofa/): The floor sofa uses cold foam: its base mattresses are HR (high-resilience) cold foam at T28 density with an ILD of 42.
- [Is T28 ILD 42 foam softer than the T30 ILD 45 in the original teddy sofa?](https://cushionguide.com/answers/t28-ild-42-vs-t30-ild-45-sofa-foam/): T28 ILD 42 foam is slightly softer on paper than T30 ILD 45, but the workshop says the difference in feel and wear is almost nothing.
- [Can the floor sofa be made with natural latex instead of foam?](https://cushionguide.com/answers/natural-latex-instead-of-foam-floor-sofa/): Yes, natural latex can replace the high-density foam in a floor sofa for an extra charge, quoted as the price difference for your size.
- [Modular Floor Sofa in Navy and Cream Velvet: Foam Notes](https://cushionguide.com/readings/navy-velvet-floor-sofa-sunlit-minimal-room/): A modular floor sofa is foam cushions under zippered covers, and the foam decides how it sits.
- [Modular Floor Sofa Stacked Three High in Velvet](https://cushionguide.com/readings/stacked-floor-sofa-navy-pine-green-rust/): A modular floor sofa sets its seat height by stacking: one base is a floor cushion, two make a low couch, and three reach armchair height, as in this cream velvet set.
- [Modular Floor Sofa in Dusty Rose Velvet for a Reading Corner](https://cushionguide.com/readings/dusty-rose-floor-sofa-pothos-shelf-reading-corner/): A modular floor sofa works as a reading corner when it borrows the patio's habits and keeps indoor fabric.
- [Can you sleep on a floor sofa? Bed size, firmness and sheets](https://cushionguide.com/guides/floor-sofa-bed-size-firmness/)
- [Boneless sofas and couches explained: foam, metal bars and the box they arrive in](https://cushionguide.com/guides/boneless-floor-sofas/)

*± 1/4 in — Nate*

---

Written by Nate Kowalski (https://cushionguide.com/masters/nate/) for CushionGuide (https://cushionguide.com/about/). The site explains made-to-measure cushions and the partner workshop makes them; measurements are in inches first. This Markdown mirrors the page at https://cushionguide.com/answers/floor-sofa-foam-density/