---
title: "How to Measure for a Back Cushion: Start at the Seat Top"
url: "https://cushionguide.com/answers/how-to-measure-backrest-cushion-height/"
section: "The Cutting Table"
author: "Harlan Pruitt, The Elder of High Point"
author_url: "https://cushionguide.com/masters/harlan/"
published: "2026-09-02"
updated: "2026-09-02"
keywords: "how to measure for back cushion, backrest cushion height, bench back cushion size, seat and back cushion set height, banquette backrest measurement"
---

# How do I measure backrest height: from the top of the seat cushion or from the bench?

*Two cushions against a wall make one height. Measure it the way they will actually sit, and the set looks like it grew there.*

Also asked as: For the backrest, how should I measure?; On top of the cushion or behind it?

> **The quick answer:** Measure backrest height from the top of the seat cushion, so the backrest sits on the bottom cushion; the shop usually recommends this because it looks and fits better. Remember the seat adds height: a 4 in (10 cm) seat cushion with the standard 16 in (40 cm) backrest stands 20 in (51 cm) in total, so shorten the back if wall space is tight.

![Long charcoal woven banquette cushion on an oak built-in bench along a café window, with black spindle chairs and pendant](https://cushionguide.com/media/banquette-cushions/charcoal-banquette-cushion-japandi-cafe-window-1600.webp "Two charcoal cushion lengths line an oak window banquette in a quiet café, with round tables pulled close.")

## Key facts

- Backrest height is usually measured from the top of the seat cushion.
- The backrest sits on the seat cushion, which looks and fits better.
- A 4 in (10 cm) seat plus the standard 16 in (40 cm) backrest stands 20 in (51 cm) in total.
- Backrest height can be reduced; one was made 15 in (38 cm) high.
- Seat depth should fit the bench: 22 in (56 cm) instead of 24 in (61 cm) avoids a 2 in (5 cm) overhang.

## Where the tape starts, measurement by measurement

| Measurement | Where the tape starts | Example |
|---|---|---|
| Backrest height | Top of the seat cushion | 16 in (40 cm), the standard |
| Total height against the wall | Top of the bench | 4 in seat + 16 in back = 20 in (51 cm) |
| Shorter backrest | Top of the seat cushion, up to your limit | 15 in (38 cm) where wall space is short |
| Seat depth | Back wall to the bench's front edge | 22 in (56 cm), not 24 in, to avoid a 2 in overhang |

## Why the back belongs on the seat

A backrest is only half a picture, my friend. Set on the seat cushion, the back and seat meet in one clean line and hold each other up. That's why the workshop usually has you measure from the top of the seat. It still depends on how you want it styled, so say so if you picture something different.

What folks forget is that the seat takes height too. A 4 in seat under a 16 in back puts the top edge 20 in above the bench. Under a window sill or a shelf, that's where trouble starts, and the fix is plain: a shorter back. The [back cushion height Pattern](https://cushionguide.com/guides/back-cushion-height-sizing/) goes further, and the [bench cushion builder](https://cushionguide.com/studio/bench-cushion-builder/) shows the stack before you order [backrest cushions](https://cushionguide.com/cushions/backrest-cushions/).

## Four inches of seat, two inches of trouble

A buyer in the US was ordering a seat and back for a banquette and did the arithmetic out loud: 4 in of seat, 16 in of back, 20 in against the wall. Then came the depth. The size on the menu was 24 in deep, the bench only 22 in, and a 2 in overhang would have hung off the front like a lip. The answer was plain. Make the seat 22 in deep, and if the wall runs short, make the back shorter too; one was made 15 in high.

> **Tailor's margin:** Backrest height starts at the top of the seat cushion; a 4 in seat and a 16 in back stand 20 in above the bench, so check the sill first.

> A backrest cushion should sit on the seat cushion, so measure its height from the top of the seat, not from the bench.
>
> — Harlan

## Buyer questions

**A common question:** Do I measure the backrest from the top of the seat cushion or from behind it?

**The workshop's answer:** It depends on how you want to style it, but the shop usually recommends measuring from the top of the seat cushion so the backrest sits on the bottom cushion. It looks and fits better that way.

**A common question:** How tall will my seat and backrest be together?

**The workshop's answer:** With a 4 in seat and the standard 16 in backrest resting on it, 20 in (51 cm). The backrest height can be changed (one was made 15 in high), and the seat depth should fit the space, such as 22 in instead of 24 in to avoid a 2 in overhang.

**A common question:** How tall should the back cushion be on a bench under a window?

**The workshop's answer:** Size it to clear the sill and window hardware. With a window lever 11 in (28 cm) above the seat, a 14-16 in (36-41 cm) tall, 3-4 in (7.5-10 cm) thick loose back worked. Under a low sill, a flat short back replaces a bolster.

**A common question:** Could the back cushion be the same size as the seat?

**The workshop's answer:** Yes, it can be made square like the seat or the same size. A full-size back is priced as a second mattress, though, so the set costs noticeably more than one with the standard 16 in backrest.

## Questions buyers ask next

### What is the standard backrest cushion height?

16 in (40 cm), measured from the top of the seat cushion. With a 4 in seat below it, the set stands 20 in (51 cm) above the bench. Shorter backs, such as 15 in (38 cm), are made when wall space is limited.

### Can a backrest be wedge-shaped instead of flat?

Yes. Send the width, height, and top and bottom thickness, or a photo or diagram with dimensions, for a quote. Wedges can be split into pieces, paired with seat cushions and shaped at the bottom for angled benches.

### What if the seat cushion size is deeper than my bench?

Order the seat to the bench instead. A seat 2 in deeper than the bench overhangs the front edge, so a 22 in (56 cm) deep bench gets a 22 in seat, not the 24 in (61 cm) size.

## Related at the atelier

- [How tall should a back cushion be on a bench under a window?](https://cushionguide.com/answers/back-cushion-height-under-window/): A back cushion on a bench under a window should stand taller than the window hardware and stay loose.
- [Should back cushions be the same thickness as the seat cushions?](https://cushionguide.com/answers/back-cushion-thinner-than-seat-cushion/): Back cushions don't have to be as thick as the seat cushions.
- [Can I buy just the back cushion without the seat?](https://cushionguide.com/answers/buy-back-cushion-only-without-seat/): Yes, a back cushion can be ordered on its own, in any size and color, with no seat cushion attached.
- [How tall should a back cushion be? Sizing backrests to your seat](https://cushionguide.com/guides/back-cushion-height-sizing/): A standard back cushion is 16 in (40 cm) tall and 4 in (10 cm) thick, made the same length as the seat, with its height measured from the top of the seat cushion.
- [Outdoor Back Cushion Proportion: Amber on a Gray Patio Sofa](https://cushionguide.com/readings/amber-outdoor-back-cushion-gray-garden-sofa/): A patio back cushion should come close to the thickness of the seat cushion below it, because that proportion props the sitter upright the way the sofa was designed.
- [Reading Wedge Backrest in Charcoal for a Bed Shared with a Dog](https://cushionguide.com/readings/charcoal-reading-wedge-dark-green-bedroom-whippet/): A firm triangular reading wedge gives upright back support in bed without replacing your pillows, and it lasts when the finishing is right: piping that follows the slope, side panels that stand flat…
- [How to keep back cushions upright on benches and banquettes](https://cushionguide.com/guides/back-cushions-staying-upright/)

*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/how-to-measure-backrest-cushion-height/