---
title: "Floor Sofa Mattress Thickness: 7.5 in Each, Not Custom"
url: "https://cushionguide.com/answers/floor-sofa-mattress-thickness/"
section: "The Cutting Table"
author: "Nate Kowalski, The Pattern Engineer of Detroit"
author_url: "https://cushionguide.com/masters/nate/"
published: "2026-03-13"
updated: "2026-03-13"
keywords: "floor sofa mattress thickness, floor sofa seat height, thicker floor sofa cushions, floor sofa mattress size, 28 density foam mattress"
---

# Can you make the floor sofa seat cushions thicker?

*Two numbers do all the work here: 7.5 and 15. One mattress, and the stack you sit on.*

Also asked as: Can you make the seat cushions thicker?; 10 inch seat cushions for a 20 inch seat height

> **The quick answer:** No, floor sofa mattress thickness can't be customized: each seat mattress is about 7.5 in (19 cm) thick, or about 15 in (38 cm) with both stacked as a sofa, in 28-density high-density foam. Requests for 8 in and 10 in seats were declined. To sit higher, add an extra stacked cushion or base mattresses instead.

![Two cream velvet floor sofas set in an L-shape, one with rust ends and one with mustard, around a shaggy rug and oak table](https://cushionguide.com/media/modular-floor-sofas/rust-mustard-floor-sofas-l-shape-corner-lounge-1600.webp "Two floor sofas meet in the corner to make an L-shaped lounge, one edged in rust and one in mustard.")

## Key facts

- Floor sofa seat thickness isn't customizable.
- Seat mattresses use 28-density high-density foam (about 1.75 lb/ft³).
- Each mattress is about 7.5 in (19 cm); two stacked are about 15 in (38 cm).
- Requests for 8 in (21 cm) and 10 in (25 cm) seats were declined.
- Each mattress is 39 x 79 in (100 x 200 cm), close to Twin XL.
- The mattresses are comfortable to sleep on.

## The numbers on the floor

| Measurement | Inches | Centimeters |
|---|---|---|
| One mattress, thickness | about 7.5 | about 19 |
| Two stacked, as the sofa seat | about 15 | about 38 |
| Mattress footprint | 39 x 79 | 100 x 200 |
| Requested seat, declined | 8 | 21 |
| Requested seat for a 20 in (51 cm) seat height, declined | 10 | 25 |

## Fixed thickness, and the way around it

The seat mattresses are cut at one standard thickness in 28-density high-density foam, about 1.75 lb/ft³. Thicker or thinner isn't offered on this model, partner; the 8 in and 10 in requests got the same polite no.

The way to a higher seat is stacking, not a fatter mattress: an extra cushion on top, or base mattresses underneath. Run your target through the [seat height calculator](https://cushionguide.com/studio/seat-height-calculator/), then read [raising a floor sofa's seat height](https://cushionguide.com/guides/floor-sofa-seat-height-raise/). For sleeping, [bed size, firmness and sheets](https://cushionguide.com/guides/floor-sofa-bed-size-firmness/) has the details; each mattress is close to [Twin XL](https://cushionguide.com/glossary/#twin-xl).

What seat height are you aiming for?

## Is a 7.5 in floor sofa mattress enough for two guests?

A buyer in the US asked whether a 7 in mattress was really enough to sleep on, and whether it could be made thicker. It couldn't. The workshop said each mattress is about 7.5 in and comfortable to sleep on.

The sofa arrived, guests used the mattresses as single beds, and the buyer wrote back that they were very convenient.

> **Tailor's margin:** A floor sofa seat is two stacked mattresses of about 7.5 in each, so the seat sits about 15 in off the floor.

> Floor sofa mattresses come in one thickness, about 7.5 in each and 15 in stacked; to sit higher, add a stacked cushion rather than a thicker mattress.
>
> — Nate

## Buyer questions

**A common question:** Can you make the floor sofa seat cushions 8 or 10 inches thick?

**The workshop's answer:** No. Seat mattress thickness can't be customized; they're made at the standard thickness in 28-density high-density foam. Requests for 10 in seats, to reach a 20 in seat height, and for 8 in (21 cm) seats were both declined.

**A common question:** Is a 7-inch mattress thick enough to sleep on?

**The workshop's answer:** The workshop says yes. Each mattress is about 7.5 in thick, or about 15 in stacked as a sofa, and they're comfortable to sleep on. The thickness can't be customized.

**A common question:** What bed size does the floor sofa make, and what sheets fit?

**The workshop's answer:** Each mattress is 39 x 79 in, near Twin XL, so Twin XL sheets fit. Two side by side make about 79 x 79 in; with the ottoman, about 79 x 119 in.

## Questions buyers ask next

### Can I stack an extra layer for a taller seat?

Yes, that's the workshop's route to a higher seat: an extra stacked cushion or base mattresses, since the mattress thickness itself is fixed. Each layer builds on the standard stack of about 15 in (38 cm).

### Is 28-density foam firm or soft?

Firm. The seat mattresses use 28-density high-density foam, about 1.75 lb/ft³. A puffier, softer filling can be requested for seats and backrests if firm isn't your preference.

### Can the mattresses be made thinner instead?

No, the thickness doesn't change in either direction on this model. Other floor cushions, such as the tufted ones, can be made thinner or thicker to order.

## Related at the atelier

- [How high is the floor sofa seat, and can it be raised?](https://cushionguide.com/answers/floor-sofa-seat-height-raise/): The floor sofa seat sits about 13 1/2 in (34-35 cm) off the floor, built from two stacked cushions of roughly 6 3/4 in (17 cm) each.
- [Is a floor sofa firm or soft to sit on?](https://cushionguide.com/answers/floor-sofa-firmness-medium-firm-foam/): A floor sofa on 28-density foam is medium-firm: the seat and ottoman cushions are medium-hard, high-density foam of about 1.75 lb/ft³ (28 kg/m³).
- [Can a floor sofa be made taller or lower?](https://cushionguide.com/answers/floor-sofa-seat-height-taller-lower/): Yes: stack an extra base cushion to make a floor sofa taller, or order it with one floor cushion instead of two to make it lower.
- [How to raise floor sofa seat height, layer by layer](https://cushionguide.com/guides/floor-sofa-seat-height-raise/): A floor sofa seat sits about 13.5 to 14.5 in (34 to 37 cm) off the floor, and the simplest way to raise it is to add a layer.
- [Is a floor sofa right for you? Floor couch height, back support and space](https://cushionguide.com/guides/floor-sofa-buying-guide-height-space/): A floor sofa suits you if everyone who sits on it can get down to a seat about 14 in (36 cm) high and back up again, and your room has space for its footprint.
- [Modular Floor Sofa in Rust and Cream Velvet: Where to Spend](https://cushionguide.com/readings/rust-velvet-end-block-cream-seat-detail/): On a modular floor sofa, spend on base thickness and order every piece at once.

*± 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-mattress-thickness/