---
title: "Slimmer Sofa Back Cushions for a Floor Sofa: 7 in, Not 15"
url: "https://cushionguide.com/answers/custom-slimmer-floor-sofa-backrests/"
section: "The Cutting Table"
author: "Harlan Pruitt, The Elder of High Point"
author_url: "https://cushionguide.com/masters/harlan/"
published: "2026-09-13"
updated: "2026-09-13"
keywords: "slimmer sofa back cushions, floor sofa backrest thinner, floor sofa backrest height, l-shaped floor sofa backrest size, taller floor sofa back cushion"
---

# Can the floor sofa backrests be made slimmer, smaller or taller?

*A backrest does two jobs, my friend: it holds you up and it takes up room. When it takes too much room there's a way to trim it, and a limit to how far.*

Also asked as: With the depth cut in half; Instead of 15 it would be 7

> **The quick answer:** Yes, floor sofa backrests can be made slimmer: L-shaped and straight backrests have been remade 7 in (18 cm) deep instead of 15 in (39 cm). Thinner backrests are less durable, though. The height isn't reduced, because it supports the person sitting, and a taller corner backrest wasn't workable, so check the height against your seated shoulders before ordering.

![Cream velvet floor cushions stacked three high with navy, pine green and rust ends, plus bolster arms and backrests](https://cushionguide.com/media/modular-floor-sofas/stacked-floor-sofa-navy-pine-green-rust-1600.webp "Three bases stacked to armchair height, with bolsters as arms and backrests in matching end colors.")

## Key facts

- Backrests have been remade 7 in (18 cm) deep instead of 15 in (39 cm).
- That set: two L-shaped backrests, 39 x 39 x 15 in (100 x 100 x 39 cm), and one straight, 39 x 15 x 15 in (100 x 39 x 39 cm).
- Thinner backrests are less durable.
- Backrest height isn't reduced, because it supports the sitter.
- A taller corner backrest wasn't workable.
- Tall buyers should check backrest height against seated shoulder height.

## “Can you cut the depth in half?”

Near enough, and it's been done. A buyer in the US had two L-shaped backrests at 39 x 39 x 15 in (100 x 100 x 39 cm) and a straight one at 39 x 15 x 15 in (100 x 39 x 39 cm). All three were remade 7 in (18 cm) deep instead of 15 in. Same length along the wall, far less cushion pushing into the seat.

## “Will a thin back hold up?”

Not as long. The workshop says it plainly: thinner backrests are less durable. That's the bargain, more room to sit against a back that tires sooner. I've watched the same trade on every kind of chair since I was sweeping shop floors. Thin is kind to the room and hard on the cushion.

## The narrow sofa that ran out of seat

A buyer in the US ordered a narrower custom floor sofa, then found the standard L-shaped backrests took up most of the seat. There was hardly room to sit. They asked for smaller backrests. The workshop explained that the height had to stay, since it holds the sitter up, but the backrests could be made thinner, with fair warning that thin ones wear out sooner. Two thin L-shaped backrests were made at a goodwill price.

## “Can the corner back be taller for my partner?”

Here the answer turned. The shop looked into a taller [corner backrest](https://cushionguide.com/glossary/#corner-backrest) for a tall buyer and couldn't find a workable solution. So the check belongs before the order. On the standard [modular floor sofa](https://cushionguide.com/cushions/modular-floor-sofas/) the L-shaped backrest rises about 14 in above a 13-14 in seat, roughly 28 in overall; compare that with your shoulder height sitting down. The [floor sofa buying pattern](https://cushionguide.com/guides/floor-sofa-buying-guide-height-space/) and the [seat height calculator](https://cushionguide.com/studio/seat-height-calculator/) help with the sum. How tall does your household sit?

> **Tailor's margin:** Floor sofa backrests can go from 15 in (39 cm) deep to 7 in (18 cm) for more seat, but thinner backrests are less durable.

> Before ordering a floor sofa, compare the backrest height with your seated shoulder height; a taller corner backrest wasn't workable.
>
> — Harlan Pruitt

## Buyer questions

**A common question:** Could you make the backrest pillows on my sofa slimmer?

**The workshop's answer:** Yes. Two L-shaped backrests (39 x 39 x 15 in / 100 x 100 x 39 cm) and one straight backrest (39 x 15 x 15 in / 100 x 39 x 39 cm) were remade 7 in (18 cm) deep instead of 15 in.

**A common question:** My narrower sofa has no seat left with the standard arms. Can the backrests be smaller?

**The workshop's answer:** The height can't come down, because it supports the person sitting. They can be made thinner, but they'll be less durable. Two thin L-shaped backrests were made this way at a goodwill price.

**A common question:** The backrest is too low for my tall partner. Is there a taller corner pillow?

**The workshop's answer:** The shop looked into a taller corner backrest but couldn't find a workable solution. Tall buyers should compare the backrest height with their seated shoulder height before ordering.

**A common question:** Should a back cushion be firm foam or soft like a pillow?

**The workshop's answer:** Either. Foam backs hold their shape better and stay put when wedge-shaped; pillow backs are softer and more relaxed. A firm foam seat can be paired with a softer pillow back.

## Questions buyers ask next

### How much seat do slimmer floor sofa backrests give back?

Going from 15 in (39 cm) to 7 in (18 cm) deep frees about 8 in (21 cm) of seat along each backrest, which is the difference between perching and sitting on a narrow sofa.

### Why won't the workshop make a floor sofa backrest shorter?

Because the height is what supports the person sitting. Requests for smaller backrests are met by making them thinner instead, with the note that thinner backrests don't last as long.

### Can slimmer backrests be ordered for a floor sofa I already own?

Yes. The slim backrests described here were remade for buyers who already had the sofa, as a separate order. Say which pieces you need, L-shaped or straight, and the depth you want.

## Related at the atelier

- [How many metal bars hold up the backrests on a floor sofa?](https://cushionguide.com/answers/floor-sofa-backrest-support-bars/): A standard modular floor sofa comes with 4 metal support bars: 2 for the sides and 2 along the back that hold the back cushions.
- [Can I buy a single straight backrest pillow for my floor sofa, and what size is it?](https://cushionguide.com/answers/straight-backrest-pillow-floor-sofa-size/): Yes, the straight backrest for the floor sofa is sold on its own and measures 39 x 15 x 15 in (100 x 39 x 39 cm).
- [Can I add a backrest to the ottoman to make a chair or small sofa?](https://cushionguide.com/answers/add-backrest-to-ottoman/): You can add a backrest to the modular floor sofa's ottoman and turn it into a lounge chair or a small L-shaped sectional.
- [Assembling floor sofa metal bars, and keeping the sofa from sliding](https://cushionguide.com/guides/floor-sofa-support-bars-assembly/): Floor sofa metal bars join by twisting and pushing each section until the small spring dots click into their holes; no screws are needed.
- [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.
- [Floor Sofa in Cobalt and Cream Velvet: One Back or Two](https://cushionguide.com/readings/cobalt-blue-cream-floor-sofa-white-room-window/): For a floor sofa about 41 x 83 in (104 x 211 cm), two 16 x 41.5 in (41 x 105 cm) backrests are easier to handle than one 16 x 83 in back, and each half can take its own color.
- [Is a floor sofa right for you? Floor couch height, back support and space](https://cushionguide.com/guides/floor-sofa-buying-guide-height-space/)
- [How to raise floor sofa seat height, layer by layer](https://cushionguide.com/guides/floor-sofa-seat-height-raise/)

*Sit well. — Harlan*

---

Written by Harlan Pruitt (https://cushionguide.com/masters/harlan/) 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/custom-slimmer-floor-sofa-backrests/