---
title: "Pillow Insert Size Chart: What Insert for Your Cover?"
url: "https://cushionguide.com/answers/pillow-insert-size-chart/"
section: "The Cutting Table"
author: "Élodie Marchand, The Colorist of New Orleans"
author_url: "https://cushionguide.com/masters/elodie/"
published: "2026-07-25"
updated: "2026-07-25"
keywords: "pillow insert size, pillow insert size chart, what size insert for 18x18 pillow cover, lumbar pillow insert size, throw pillow insert bigger than cover"
---

# What size insert does my pillow cover need?

*A pillow is judged from across the room before anyone touches it. The insert decides whether it reads crisp or tired.*

Also asked as: 18 x 18 pillow covers; 3 custom lumbar pillow covers

> **The quick answer:** For a full, plump pillow, choose an insert about 2 in (5 cm) larger than the cover: an 18 x 18 in cover takes a 20 x 20 in insert. Big squares can go up to 4 in larger; for a slouchy pillow, use the same size. On lumbars, which guides debate, 1 to 2 in larger each way fills them.

![Mustard yellow outdoor seat pads with bow ties on brown wrought-iron chairs around a bistro table in a rose garden](https://cushionguide.com/media/dining-chair-cushions/mustard-yellow-tie-on-pads-wrought-iron-garden-chairs-1600.webp "Four mustard seat pads tied in bows give a set of dark wrought-iron garden chairs a cheerful lift.")

## Key facts

- For a full look, published charts size a square insert about 1 to 2 in larger than its cover; 2 in is the common rule (18 in cover, 20 in insert).
- Large squares can go further: one chart pairs a 30 in cover with a 34 in insert.
- A same-size insert gives a softer, slouchier pillow.
- Lumbar advice is split; a 14 x 36 in cover with a same-size insert tends to look flat, and a 16 x 38 in insert fills it.
- Feather and down compress more than polyester, which is why those fills are usually sized up.
- The workshop fills pillows with shredded foam in a separate inner cover; polyester fiber or solid foam can be requested.
- Covers alone are made to any size for inserts you already own, always with a zipper.

## The insert chart, cover by cover

Measure the empty cover, then read across.

| Cover | Insert for a full, plump look |
|---|---|
| 14 x 14 in (36 x 36 cm) | 15 or 16 in square (38 or 41 cm) |
| 18 x 18 in (46 x 46 cm) | 20 in square (51 cm) |
| 20 x 20 in (51 x 51 cm) | 22 in square (56 cm) |
| 22 x 22 in (56 x 56 cm) | 24 in square (61 cm) |
| 26 x 26 in euro sham (66 x 66 cm) | 28 in square (71 cm) |
| 30 x 30 in (76 x 76 cm) | 32 to 34 in square (81 to 86 cm) |
| 24 x 12 in lumbar (61 x 30 cm) | 25 x 13 in (64 x 33 cm) |
| 14 x 36 in lumbar (36 x 91 cm) | 16 x 38 in (41 x 97 cm) |

For a soft, slouchy pillow, use an insert the same size as the cover. Charts differ by an inch here and there; the 24 x 12 in row is a real workshop order.

## Why two extra inches read as generous

An 18 in (46 cm) insert in an 18 in cover lets the fabric relax, and the corners go soft. A 20 in insert pulls the cloth taut to every corner, so a linen weave or a velvet pile catches the light evenly. The eye sits down first, and it prefers a full pillow.

Fill changes the arithmetic. Feather and down compress more than polyester, so charts built around them size up by 2 in or more. The workshop fills its own pillows with shredded foam in a separate inner cover, or polyester fiber or solid foam on request. Covers are cut to your own feather or down inserts; to have the workshop supply one, ask the workshop first. See [throw pillows](https://cushionguide.com/cushions/throw-pillows/) and [covers for inserts you already own](https://cushionguide.com/answers/throw-pillow-covers-for-existing-inserts/).

## Lumbars: where the charts part ways

On long pillows the guides disagree. Some say match the insert to the cover; others size up, and one chart that says match still pairs a 12 x 20 in cover with a 12 x 22 in insert. Another says a 14 x 36 in lumbar looks flat with a same-size insert and full with 16 x 38 in.

My rule: about 1 in larger each way on a small lumbar, 2 in on a long one. Match only for a flat, tailored lumbar against a bench back. Sizes are on [lumbar pillows](https://cushionguide.com/cushions/lumbar-pillows/).

Which look does your sofa ask for, my friends: crisp and upright, or soft enough to sink into?

## Three ticking-stripe lumbars to match a bench

A buyer in the US asked for three lumbar pillows in the same ticking stripe as their bench cushion. The covers measured 24 x 12 in (61 x 30 cm); the inserts, 25 x 13 in (64 x 33 cm), one inch larger each way, for a full look.

A stripe is honest about fit. Underfilled, its lines wander; filled well, each one runs straight.

> **Tailor's margin:** Measure the empty cover flat and zipped, seam to seam. Add 2 in (5 cm) for a full pillow, nothing for a slouchy one.

> A same-size insert whispers. An insert two inches larger speaks up. Decide which voice the sofa needs.
>
> — Élodie

## Buyer questions

**A common question:** Can you make zippered covers for the throw pillow inserts I already have?

**The workshop's answer:** Yes. Order on the zippered cover listing, put the sizes in the Exact Size field, note that they are pillow covers with your color and piping codes, then message the shop. Pillow covers are flat, with no side depth.

**A common question:** Could you make lumbar pillows to match my bench cushion, and make them look full?

**The workshop's answer:** Yes, in the same fabric, filled or as covers only, with zippered covers that come off to wash. One order put 25 x 13 in (64 x 33 cm) inserts in 24 x 12 in (61 x 30 cm) covers for a full look.

**A common question:** My new throw pillows arrived flat and underfilled. What happened?

**The workshop's answer:** The fill shifts toward the middle during vacuum-packed shipping. Pat and shake each pillow back into its corners and allow 1-2 days. The corners stay a touch less full than the body, but there shouldn't be gaps.

## Questions buyers ask next

### Does a feather or down insert need more oversize than a polyester one?

Usually. Feather and down compress more than polyester, which is why charts written for those fills size up by 2 in or more. With polyester, try the insert in the cover before committing to the full step.

### How do I measure a pillow cover before buying the insert?

Lay the empty cover flat and zipped and measure seam to seam across each side. Add about 2 in (5 cm) for a full insert, nothing for a soft one.

### What lumbar size suits a queen bed or a three-seat sofa?

One published guide suggests 14 x 24 in for a queen bed, 14 x 36 in or 12 x 46 in for a king, and 14 x 36 in for a three-cushion sofa. Treat those as starting points.

## Related at the atelier

- [Custom Throw Pillows: Mixing a Palm Jacquard With Plains](https://cushionguide.com/readings/sage-palm-jacquard-pillow-rattan-armchair-olive-tree/): To mix patterns on a garden chair, let one patterned pillow carry the design, keep the seat cushion plain, and add texture rather than a second print.
- [Custom Throw Pillow in Navy Leaf Jacquard on a Teak Lounge Chair](https://cushionguide.com/readings/navy-leaf-jacquard-pillow-teak-lounge-chair-sea-view/): One patterned throw pillow is enough to remake a chair whose seat and back cushions are plain.
- [Bouclé Throw Pillow in Caramel Against Navy Velvet Seating](https://cushionguide.com/readings/caramel-boucle-pillow-navy-velvet-chair/): On navy velvet seating, a caramel or tan bouclé throw pillow is the safest warm accent: it sits nearly opposite navy on the color wheel, so it lifts the dark upholstery without shouting.
- [Matching throw pillows and lumbars to a seat cushion, color by color](https://cushionguide.com/guides/matching-throw-pillows-lumbar-pillows/): Matching throw pillows work best as a trio: one pillow in the seat cushion's own fabric, one that repeats the piping color, and one quiet texture.
- [How do I get the foam back into my cushion cover?](https://cushionguide.com/answers/how-to-put-foam-back-in-cushion-cover/): To put foam back in a cushion cover, fold the foam, not the cover: open the zipper past both corners, slip the foam into a thin plastic bag, fold it lengthwise and fill the far corners first.
- [Can you make matching throw pillows in the same fabric as my cushion?](https://cushionguide.com/answers/matching-throw-pillows-same-fabric-cushion/): Yes, matching throw pillows can be made in the same fabric as your cushion, in any color and any size, as covers only or filled.
- [How to match a new cushion to your sofa, paint or wallpaper](https://cushionguide.com/guides/match-cushion-to-sofa-paint-wallpaper/)

*With color and care — Élodie*

---

Written by Élodie Marchand (https://cushionguide.com/masters/elodie/) 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/pillow-insert-size-chart/