---
title: "Daybed Mattress Cover Measurements: Length, Width, Thickness"
url: "https://cushionguide.com/answers/daybed-mattress-cover-measurements/"
section: "The Cutting Table"
author: "Nate Kowalski, The Pattern Engineer of Detroit"
author_url: "https://cushionguide.com/masters/nate/"
published: "2026-08-21"
updated: "2026-08-21"
keywords: "daybed mattress cover measurements, daybed cover size, twin daybed mattress cover, custom daybed mattress cover, stacked mattress cover thickness"
---

# What measurements do you need for a daybed mattress cover?

*Three numbers make a daybed cover. Leave out the third and the cover can come back sized for a mattress twice as thick as yours.*

Also asked as: What dimensions do you need for the cover?; Do you need the depth of two mattresses together?

> **The quick answer:** A daybed mattress cover needs three measurements: the mattress length, width and thickness, in inches or centimeters. A twin at 39 x 75 x 12.5 in works, and so does 78¾ x 31½ x 8¾ in (200 x 80 x 22 cm). Always state the thickness; without it, the workshop may assume a double-layer mattress. Two stacked mattresses in one cover need their combined thickness.

![Charcoal gray linen-look daybed seat cushion and round bolster on a light oak platform with knit throw and Persian rug](https://cushionguide.com/media/daybed-cushions/charcoal-daybed-cushion-bolster-oak-platform-1536.webp "A single long bolster replaces a row of back pillows, keeping the daybed low and clean-lined.")

## Key facts

- A daybed cover needs the mattress length, width and thickness (height).
- Measurements are accepted in inches or centimeters.
- Without a stated thickness, the workshop may assume a double-layer mattress and make the cover twice as thick.
- Two mattresses stacked in one cover need their combined thickness.
- For IKEA beds, the workshop asks for the mattress model to check the real thickness.
- On daybed sets, backrests and armrests are sized from the mattress cover.
- For an existing sofa, send photos; for a tight space, measure the clearance first.

## The daybed cover checklist, in order

- ✓ **Length** of the mattress, end to end
- ✓ **Width**, side to side
- ✓ **Thickness** (height), top to bottom, never left blank
- ✓ **Unit**: inches or centimeters, stated once and clearly
- ✓ **Mattress model**, if it sits on an IKEA bed
- ✓ **Photos** of the furniture, if the cushions are for an existing sofa
- ✓ **Clearance** of the space, if the piece is going somewhere tight

## Four orders, four outcomes

| What you have | What to send | What happens |
|---|---|---|
| Twin daybed mattress | 39 x 75 x 12.5 in (99 x 190.5 x 32 cm) | Cover made to all three numbers |
| Metric mattress | 78.75 x 31.5 x 8.75 in (200 x 80 x 22 cm) | Fine as sent; the unit is stated |
| Two stacked 6 in (15 cm) mattresses | Length x width x 12 in (30 cm) | One cover, combined thickness |
| Length and width only | Nothing for thickness | Cover may be made for a double-layer mattress |

## Why the third number decides the fit

Length and width are the easy two. Thickness is where daybed covers go wrong: leave it off the order and the workshop may assume a double-layer mattress and make the cover twice as thick. Measure twice; the fabric remembers.

Stacked mattresses count as one block, partner. Two 6 in (15 cm) mattresses in one cover need a 12 in (30 cm) cover. For an IKEA bed, add the mattress model so the real thickness can be checked; a [Twin XL](https://cushionguide.com/glossary/#twin-xl) at 6 in deep is a different cover from a twin at 12.5 in.

On a daybed set, sequence matters. The mattress cover is sized first, and the backrests and armrests are sized to match it, so settle those three numbers before choosing back cushions on the [daybed cushions](https://cushionguide.com/cushions/daybed-cushions/) page. The full method is in the [daybed mattress cover measuring pattern](https://cushionguide.com/guides/daybed-mattress-cover-measurements/), and Hemnes owners should see [IKEA Hemnes daybed covers](https://cushionguide.com/cushions/ikea-hemnes-daybed-covers/).

What does your mattress measure on its thin side?

> **Tailor's margin:** A daybed cover order without a thickness can come back sized for a double-layer mattress. Write the third number, even when it feels obvious.

> Daybed mattress cover measurements are three numbers: length, width and thickness. Two stacked mattresses get one combined thickness.
>
> — Nate

## Buyer questions

**A common question:** Do you need just the overall size of my daybed mattress, or more than that?

**The workshop's answer:** The overall length x width x height of the mattress, in inches or centimeters. If two mattresses are stacked inside one cover, the workshop needs their combined thickness, and for IKEA beds it asks which mattress model you have so it can check the real thickness. On daybed sets the cover size comes first; backrests and armrests are sized to match it.

**A common question:** My mattress is a standard twin. What exactly should I send for a custom cover?

**The workshop's answer:** Length, width and thickness, for example a twin at 39 x 75 x 12.5 in, or 78¾ x 31½ x 8¾ in (200 x 80 x 22 cm) in metric. If no thickness is given, the workshop may assume a double-layer mattress and make the cover twice as thick, so always state it.

**A common question:** I need new base cushions for a second-hand sofa. What do you need from me?

**The workshop's answer:** The overall length x width x depth of the seat, plus photos of the furniture so the fit comes out right. If the sofa sits in a tight space, measure the available clearance first and include it.

**A common question:** Should I measure my old cover or the foam inside it?

**The workshop's answer:** For new covers on existing foam, measure the bare insert, not the old cover, and include its thickness. If your old cushions fit well, their sizes are a fine reference; otherwise measure the frame itself.

## Questions buyers ask next

### Can I give daybed measurements in centimeters instead of inches?

Yes. Inches and centimeters both work; just state which one you used. The workshop confirms units before quoting, so a cover drawn in centimeters isn't accidentally cut in inches.

### Do daybed backrests get their own measurements?

They follow the mattress. On daybed sets the mattress cover size is fixed first, and the backrests and armrests are sized to match it, so get the mattress numbers right before anything else.

### What if my daybed sits in a tight alcove?

Measure the clearance of the space first and send it with photos of the furniture. That lets the workshop check the finished piece against the room it is going into, not just against the mattress.

## Related at the atelier

- [How much is a zippered cover only for a daybed mattress?](https://cushionguide.com/answers/daybed-mattress-cover-only-price/): A zippered daybed mattress cover can be ordered on its own, priced by its size: choose the 'cover' or 'mattress cover' option on the daybed listing, then write the exact size, such as 75 x 39 x 5…
- [Can you make a daybed mattress cover to fit my mattress?](https://cushionguide.com/answers/custom-daybed-mattress-cover-size/): Yes, a daybed mattress cover is made to your mattress's exact length, width and height, twin, full or queen.
- [Daybed Cushion in Red and Cream Stripe: A Sunroom Notebook](https://cushionguide.com/readings/red-cream-striped-daybed-cushion-rattan-sunroom/): A striped daybed cushion looks deepest when the stripes run front to back and drop straight down the box edge.
- [Daybed Cushion in Denim Blue on Walnut, With a Round Bolster](https://cushionguide.com/readings/denim-daybed-cushion-walnut-base-olive-tree/): A daybed cushion reads as a sofa when a round bolster spans its full length as the backrest and a single lumbar pillow sits in front, keeping the seat deep.
- [Daybed Cushion in Oxblood Faux Leather with Dark Piping](https://cushionguide.com/readings/oxblood-faux-leather-daybed-dark-piping-parquet/): An oxblood faux leather daybed cushion stays sharp all year when its piping is one shade darker than the body and its boxed top panel is cut in one piece, since leather-look fabric shows every join.
- [One daybed, three jobs: a cushion set for sofa days and guest nights](https://cushionguide.com/concepts/daybed-sofa-cushion-sets/): A daybed cushion set that works as a sofa is a fitted mattress cover, two back cushions about 20 in (50 cm) tall and a bolster at each arm.
- [What to measure for a custom daybed mattress cover](https://cushionguide.com/guides/daybed-mattress-cover-measurements/)
- [How to measure an IKEA Hemnes daybed: two stacked mattresses, one cover](https://cushionguide.com/guides/ikea-hemnes-daybed-cover-measuring/)

*± 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/daybed-mattress-cover-measurements/