---
title: "Replacement Cushion Cover Measurements: The Three Numbers"
url: "https://cushionguide.com/answers/measurements-for-custom-cushion-cover/"
section: "The Cutting Table"
author: "Élodie Marchand, The Colorist of New Orleans"
author_url: "https://cushionguide.com/masters/elodie/"
published: "2026-07-13"
updated: "2026-07-13"
keywords: "how to measure for a replacement cushion cover, cushion cover only measurements, zippered cover for existing foam, replacement cushion cover custom size, cushion cover without foam"
---

# What measurements do you need to make a cover for my own foam?

*A cover is a portrait of the foam inside it. Three numbers draw that portrait, and the third is the one people forget.*

Also asked as: Only the covers, without foam, with a zip; Just the cover for my mattress

> **The quick answer:** To order a replacement cushion cover, send the exact length, width and thickness of each foam piece; the thickness, or fillable depth, is what makes the cover snug. Pick the closest size range on the zippered cover listing, then write the exact sizes and your fabric code in the personalization box. Place one order per cover size.

![Four velvet box cushions stacked in dusty rose, sage with pink piping, mustard and cobalt on an oak worktable](https://cushionguide.com/media/bench-cushions/four-velvet-box-cushions-rose-sage-mustard-cobalt-1600.webp "Four velvet colors on the workroom table; only the sage one wears contrast piping, in blush pink.")

## Key facts

- A cover needs the exact length, width and thickness of the insert.
- Thickness (the fillable depth) is essential for a snug fit.
- Select the closest size range, then write exact sizes and the fabric code in Add Personalization.
- Corner ties can be added to covers.
- Place one order per cover size.
- Non-standard thicknesses such as 5.5 in (14 cm) are fine for covers only.
- A cover-only order includes no foam or filling.

## Six lines for a cover-only order

1. Length of the foam, edge to edge across the top.
2. Width, front to back.
3. Thickness, the fillable depth: the number that makes the cover snug.
4. Fabric code, plus a piping code if you want piping.
5. Corner ties, if the cushion has to stay put on a chair or bench.
6. One order per size: two different sizes means two orders.

## Cover-only orders the workshop has made

| Insert | Sizes sent | Worth knowing |
|---|---|---|
| Chair cushions | 22.5 x 18.5 x 3 in (57 x 47 x 7.5 cm) | Ordered on the zippered cover listing |
| Second chair size | 22.5 x 22 x 3 in (57 x 56 x 7.5 cm) | A separate order for the second size |
| Mattress | 55 x 27.5 in (140 x 70 cm), plus its height | Height needed for a snug fit |
| Odd-thickness foam | 5.5 in (14 cm) thick | Fine for a cover; not used for full cushions |

## Thickness is the side of the portrait

Length and width describe the top of your foam. Thickness describes its sides, the band of fabric called the [gusset](https://cushionguide.com/glossary/#gusset) that wraps around it. Guess that number and a cover either strains or slouches, and no color in the world rescues a slouching cover.

On the zippered cover listing, choose the closest size range, then write the exact sizes and fabric code in Add Personalization. A cover-only order holds no foam or filling, and it is priced below a full cushion. The [covers-only measuring Pattern](https://cushionguide.com/guides/cushion-covers-for-existing-foam/) has the diagrams, and the [cushion covers](https://cushionguide.com/cushions/cushion-covers/) hub shows the styles. What does your foam measure on its side, my friends?

> **Tailor's margin:** A replacement cushion cover needs three numbers, length, width and thickness; the thickness is the fillable depth that makes the cover snug.

> An odd 5.5 in foam thickness is no problem for a cover-only order, even though full cushions aren't made at that thickness.
>
> — Élodie

## Buyer questions

**A common question:** Can I buy just a cover, no foam, for an unusual thickness?

**The workshop's answer:** Yes, from the custom zippered cover listing. Select the closest size range and write your exact measurements, thickness included, in Add Personalization. A 5.5 in (14 cm) thickness isn't used for full cushions, but for a cover only it's no problem.

**A common question:** Can you make zippered covers only for the mattress I already have?

**The workshop's answer:** Yes. Choose the size range on the zippered cover listing and write the exact length, width and thickness plus the fabric code. The height is needed for a snug fit, for example on a 55 x 27.5 in (140 x 70 cm) mattress. A cover-only order includes no foam or filling.

**A common question:** I have cushions already. Can I order just new covers?

**The workshop's answer:** Yes, there's a dedicated custom zippered box-cover listing for covers only. Send the exact length, width and thickness; chair covers of 22.5 x 18.5 in and 22.5 x 22 in, both 3 in (7.5 cm) deep, were ordered through it.

**A common question:** Do you make zippered covers without foam so I can use my own filling?

**The workshop's answer:** Yes, covers without foam are a core product, at a reduced price compared with a full cushion. Write the exact size, fillable depth and fabric code in the personalization, add corner ties if needed, and place one order per cover size.

**A common question:** Can I get a spare set of covers in another color later on?

**The workshop's answer:** Yes. The workshop keeps your exact sizes, so extra covers in any chart color can be made now or later. Ordered with the cushion, a second cover is about half the cushion price, via a private link.

## Questions buyers ask next

### Should I measure the foam or the old cover?

Measure the foam or mattress itself. The workshop asks for the exact length, width and thickness of each insert, because the new cover is cut to fit what goes inside it, not what used to sit around it.

### Can a cover-only order include ties?

Yes. Corner ties can be added to a zippered cover; mention them in the personalization box along with your sizes and fabric code. They help a chair or bench cushion stay where you put it.

### Can two cover sizes go through one checkout?

Place one order per cover size. Chair covers of 22.5 x 18.5 in and 22.5 x 22 in, both 3 in deep, went through as separate orders on the same zippered cover listing.

## Related at the atelier

- [Can I buy just the cushion cover without the foam insert?](https://cushionguide.com/answers/cushion-cover-only-without-foam/): Yes: a cushion cover only, without foam, is sewn to the exact length, width and thickness of the insert you already own.
- [Will a replacement cover fit my own insert snugly?](https://cushionguide.com/answers/replacement-cover-fit-own-insert/): Yes, a replacement cover can fit your own insert snugly if the measurements are right: the fabric has a slight stretch, so fitted covers are cut about 3/8 to 3/4 in (1 to 2 cm) under the measured…
- [Can you make slipcovers for the sofa I already own?](https://cushionguide.com/answers/slipcovers-for-existing-sofa/): No: the workshop doesn't make fitted slipcovers for a whole conventional sofa (arms, back and skirt) or for an unrelated multi-piece set, such as a five-piece sofa with a storage ottoman.
- [Ordering new cushion covers for foam you already own](https://cushionguide.com/guides/cushion-covers-for-existing-foam/): To order replacement cushion covers, measure the bare insert seam to seam while it lies relaxed, record its true thickness without rounding, and say whether it is foam, fiber or a mattress.
- [Zippered Cushion Covers With Contrast Piping: What Goes Inside](https://cushionguide.com/readings/four-zippered-box-cushion-covers-contrast-piping/): A zippered box cushion cover is only half a cushion: its box height sets how much foam goes inside, and doubling the height from 6 in to 12 in roughly doubles the fill and the cost.
- [Custom Cushion Covers in Dusty Velvet With Contrast Piping](https://cushionguide.com/readings/dusty-velvet-cushion-covers-contrast-piping-pile/): Custom cushion covers fit best when the cover's side wall matches your insert's thickness and the length and depth are agreed as finished sizes, since handmade covers carry a 1/2 to 1 in (1.3 to 2.5…
- [Cut-to-size foam vs a finished cushion: the honest comparison](https://cushionguide.com/guides/cut-to-size-foam-vs-finished-cushion/)

*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/measurements-for-custom-cushion-cover/