Guides / Reference

Sleeper Sofa Mattress Sizes

Three of the size names in this category describe something smaller than the name implies. Here is the full reference, so you order the right one once.

This is a reference page, and it exists because three size names in this category describe something smaller than you would reasonably assume. People order a queen and receive something eight inches shorter; people order a twin-width mattress for a tri-fold and receive something seven inches narrower.

The three traps, up front. A sofa-bed queen is 52 by 73 inches, not 60 by 80. A cot-size tri-fold is 31 inches wide, not 38. And a cabinet bed sold as queen can contain a 53-by-75-inch mattress, which is nearer a full.

The full size reference

Every size in this category, measured

Bedroom twin: 38 × 75 in.
Bedroom twin XL: 38 × 80 in.
Bedroom full: 54 × 75 in.
Bedroom queen: 60 × 80 in.
Full futon mattress: 75 × 54 in. — same plan as a bedroom full
Sofa-bed queen: 52 × 73 in. — 8 in. shorter than a bedroom queen
Cot-size tri-fold: 75 × 31 in. — 7 in. narrower than a twin
Cabinet bed tri-fold (Creden-ZzZ): sleeping surface not published despite the queen label
Cabinet bed tri-fold (Night & Day Cube): 80 × 63 × 6 in.
Floor futon twin / full / queen: 39 × 80 / 54 × 80 / 60 × 80 in.

Two useful patterns. Futon mattresses and floor futons use real mattress plans, so ordinary sheets fit. Sofa-bed and cabinet-bed mattresses do not, because they are dimensioned to a cavity rather than to a bedding standard. The futon side has its own wrinkle — a floor futon runs 80 inches long in every width, so its full is five inches longer than a bifold full — and that chart is in futon mattress sizes.

Convertible sofas do not have a size at all

A split-back convertible has no mattress, so it has no mattress size — it has an opened dimension, and every model’s is different.

Opened dimensions, which are not sizes

Serta Rane / Terrell: 66.1 × 37.6 in.
Mopio splitback: 85 × 38.2 in.
HALLYBEE futon: 85 × 38.2 in.
CouCouchmans memory foam futon: open size not published
OSP Sawyer: 66 × 38.75 in.
CosmoLiving Liberty sectional: 76.5 × 68.5 in.

No fitted sheet is made for any of these, and there is no trick that makes one work. What people use in practice is a flat sheet tucked, or a duvet folded in half and used as both layers. A fitted full sheet on a 38.2-inch-wide surface pulls at the corners and comes off in the night.

Depth limits by frame, which matter as much as plan size

How thick you can go

Fold-out sofa bed: About 4.5 in. — the mattress folds into a cavity
Bi-fold futon frame: Up to 8 in. — folds once, in the open
Tri-fold / cabinet bed: About 6 in. — folds twice
Trundle drawer: 6 in. or less, or the tray will not close
Daybed: The frame's side rail height — GIANTEX twin daybed publishes 8 in.
Wall bed: 8–12 in. conventional; Bestar states 60–90 lb as well

A wall bed is the only format here with a mattress weight limit as well as a depth limit, because the mechanism is counterbalanced. Bestar's Key West specifies 60 to 90 pounds; Olela specifies 80 pounds maximum for a queen.

What bedding actually fits what

Full futon mattress (75 × 54 in.). Standard full sheets fit. Use a shallow-pocket or low-profile fitted sheet on an eight-inch mattress — most fitted sheets are now cut for 10 to 14 inches and will billow.

Sofa-bed queen (52 × 73 in.). Queen sheets, loose but usable. No mattress protector exists in this size in general retail; a flat waterproof pad under the sheet is the practical answer.

Cot-size tri-fold (75 × 31 in.). Cot sheets exist and are hard to find. Most people use a flat sheet.

Daybed (38 × 75 in.). Ordinary twin sheets, which after everything above is a relief.

Wall bed (60 × 80 in.). Ordinary queen everything, and the bedding stays on the bed under straps, which is one of the format’s best features.

How to measure the frame you already have

Open the sofa fully. Measure the existing mattress flat: width across, length along, and depth at the edge rather than the middle, because the middle has compressed.

Then close the sofa and measure the cavity the mattress lives in. That second number is your real depth ceiling, and it is usually about half an inch less than the mattress currently in there, because the old one has thinned.

Order to the smaller number. A replacement half an inch too thick stops the sofa closing, and there is no adjustment. Replacements are covered in the best sleeper sofa mattresses.

Record the width while the tape is out, because bedding uses a different convention again: sheet sellers cut a “sofa-bed queen” at 60 by 74 inches, which is eight inches wider than the 52-inch replacement slabs above. The best sleeper sofa sheets sets out which cut to order against a measured mattress.

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At a glance

Replacements in the sizes that exist

Tap any row to jump to the full write-up. Scores are our own, from the rubric on how we choose — not customer ratings. They score each product across the whole site, so the order here reflects how well a pick answers this page’s question, which is not always the same as the highest score.

#	Product	Best for	Score	Price
01	Milliard 4.5 Inch Memory Foam Sleeper Sofa Replacement Mattress (Full) The fix for a pull-out you can feel the bar through: 1.5 inches of memory foam over a 3-inch firm base, in a waterproof washable cover.	Replacing a pull-out mattress	7.7	$189.99 · View on Amazon #ad how we earn · price as of November 14, 2026
02	Royal Sleep Products 10 Inch Pocket Coil Futon Mattress (Full) Ten inches of pocket coils, CertiPUR-US foam and cotton batting — the closest a drop-in futon mattress gets to a real bed, and it fits any standard full futon frame.	Everyday sleeping on a futon frame	8.1	$304.99 · View on Amazon #ad how we earn · price as of November 14, 2026
03	Milliard 6-Inch Tri-Fold Memory Foam Mattress (Twin XL) The one that goes in a closet: 78 by 38 inches flat, six inches of memory foam over a support base, and it folds into roughly a third of that in seconds.	Storing a guest bed in a closet	7.8	$214.99 · View on Amazon #ad how we earn · price as of November 14, 2026
04	Zinus 8 Inch Green Tea Memory Foam Mattress (Twin) Eight inches of green-tea and ActivCharcoal infused memory foam — the standard answer for a daybed or trundle that needs a real mattress under ten inches.	Daybeds and trundles	8.0	$138.99 · View on Amazon #ad how we earn · price as of November 14, 2026

How we picked

One representative mattress per size class — fold-out sofa bed, full futon, cot-size tri-fold and conventional — so the reference table maps onto something orderable. Chosen for published dimensions rather than comfort, because this page exists to stop the wrong size arriving.

Replacing a pull-out mattress

Milliard 4.5 Inch Memory Foam Sleeper Sofa Replacement Mattress (Full)

Milliard

The fix for a pull-out you can feel the bar through: 1.5 inches of memory foam over a 3-inch firm base, in a waterproof washable cover.

What it's bad at

A "full" sofa-bed mattress is 52 by 73 inches, not 54 by 75. Your full sheets will be loose on it, and a standard full mattress protector will not fit properly either.

Our score — 7.7 / 10

Footprint8

Mattress8

Mechanism8

Renter fit10

Value7

$189.99 · View on Amazon

#ad how we earn · price as of November 14, 2026

Specifications

Folded footprint: Ships compressed
Open footprint: 73 in. L x 52 in. W x 4.5 in. H (sofa-bed full)
Clearance in front: Not applicable — mattress.
Doorway minimum: Ships compressed, so any doorway
Sleep surface: 52 x 73 in. — sofa-bed full, smaller than a bedroom full
Mattress: 4.5 in.; 1.5 in. soft memory foam over a 3 in. firm polyurethane base
Fold mechanism: Folds into most fold-out sofa frames
Weight capacity: NOT STATED BY MANUFACTURER
Assembly: None. Breathable, waterproof, washable jacquard cover included.
Renter-safe?: Yes
Price: $189.99 · View on Amazon
#ad how we earn · price as of November 14, 2026

Source: Amazon.com product listing, read via the Amazon Creators API, recorded 16 Oct 2026. Any field the listing does not state is marked as such rather than estimated.

Everyday sleeping on a futon frame

Royal Sleep Products 10 Inch Pocket Coil Futon Mattress (Full)

Royal Sleep Products

Ten inches of pocket coils, CertiPUR-US foam and cotton batting — the closest a drop-in futon mattress gets to a real bed, and it fits any standard full futon frame.

What it's bad at

Ten inches is a lot of mattress to ask a folding frame to bi-fold. Check the frame's maximum mattress depth before ordering, because many metal futon frames top out at eight.

Our score — 8.1 / 10

Footprint7

Mattress9

Mechanism7

Renter fit10

Value7

$304.99 · View on Amazon

#ad how we earn · price as of November 14, 2026

Specifications

Folded footprint: Not stated — ships as a mattress, frame not included
Open footprint: 75 in. L x 54 in. W x 10 in. H (full)
Clearance in front: Not applicable — this is a mattress, not a frame.
Doorway minimum: NOT STATED BY MANUFACTURER
Sleep surface: 75 x 54 in. — standard full
Mattress: 10 in.; pocket coils with layers of CertiPUR-US certified memory foam and cotton batting. Flippable, hand-tufted, made in the USA.
Fold mechanism: Folds with the frame
Weight capacity: NOT STATED BY MANUFACTURER
Assembly: None. 39 lb. Spot clean only.
Renter-safe?: Yes
Price: $304.99 · View on Amazon
#ad how we earn · price as of November 14, 2026

Source: Amazon.com product listing, read via the Amazon Creators API, recorded 16 Oct 2026. Any field the listing does not state is marked as such rather than estimated.

Storing a guest bed in a closet

Milliard 6-Inch Tri-Fold Memory Foam Mattress (Twin XL)

Milliard

The one that goes in a closet: 78 by 38 inches flat, six inches of memory foam over a support base, and it folds into roughly a third of that in seconds.

What it's bad at

The two fold lines are findable through the foam if you sleep on your side, and Milliard publishes no weight capacity and no folded dimensions for this size.

Our score — 7.8 / 10

Footprint10

Mattress7

Mechanism8

Renter fit10

Value6

$214.99 · View on Amazon

#ad how we earn · price as of November 14, 2026

Specifications

Folded footprint: Folded dimensions not stated by the manufacturer
Open footprint: 78 in. L x 38 in. W x 6 in. H flat
Clearance in front: Not applicable — floor mattress.
Doorway minimum: Folds in seconds for transport, so any standard doorway
Sleep surface: 78 x 38 in. — twin XL, full twin width and four inches longer
Mattress: 6 in.; high-density memory foam with a removable machine-washable cover
Fold mechanism: Tri-fold
Weight capacity: NOT STATED BY MANUFACTURER
Assembly: None. Also sold in Twin, Full and Queen.
Renter-safe?: Yes
Price: $214.99 · View on Amazon
#ad how we earn · price as of November 14, 2026

Source: Amazon.com product listing, read via the Amazon Creators API, recorded 16 Oct 2026. Any field the listing does not state is marked as such rather than estimated.

Daybeds and trundles

Zinus 8 Inch Green Tea Memory Foam Mattress (Twin)

Zinus

Eight inches of green-tea and ActivCharcoal infused memory foam — the standard answer for a daybed or trundle that needs a real mattress under ten inches.

What it's bad at

Zinus rates the twin to 250 lb where every other size takes 500, and twin is exactly the size daybeds and trundles take.

Our score — 8.0 / 10

Footprint7

Mattress9

Mechanism6

Renter fit10

Value9

$138.99 · View on Amazon

#ad how we earn · price as of November 14, 2026

Specifications

Folded footprint: Ships compressed and rolled in a box
Open footprint: 75 in. L x 39 in. W x 8 in. H (twin)
Clearance in front: Not applicable — mattress.
Doorway minimum: Ships rolled, so any doorway
Sleep surface: 39 x 75 in. — standard twin
Mattress: 8 in.; green tea and ActivCharcoal infused memory foam. CertiPUR-US and OEKO-TEX certified.
Fold mechanism: None — does not fold
Weight capacity: 250 lb in Twin; 500 lb in all other sizes
Assembly: None. 26.7 lb. Allow 24 to 72 hours to regain full shape. 10-year limited warranty.
Renter-safe?: Yes
Price: $138.99 · View on Amazon
#ad how we earn · price as of November 14, 2026

Source: Amazon.com product listing, read via the Amazon Creators API, recorded 16 Oct 2026. Any field the listing does not state is marked as such rather than estimated.

Answers

Common questions

What size is a queen sleeper sofa mattress?

52 by 73 inches — for example the Milliard 4.5-inch replacement, at 52 by 73 by 4.5 inches. A bedroom full is 54 by 75. They are not interchangeable, and ordering a bedroom queen means the sofa will not close.

What size sheets fit a sleeper sofa?

Measure the mattress first, because the sheet sellers and the replacement-mattress sellers do not use the word queen the same way: sofa-bed sheet sets are cut 60 by 74 inches, while a common replacement sofa-bed queen is 52 by 73. If yours measures near 52 or 54 inches wide, buy a full-size sofa-bed set. For a convertible split-back, nothing fits — those open to non-standard sizes like 85 by 38.2 inches, and the practical answer is a flat sheet or a folded duvet. A full futon mattress at 75 by 54 inches takes standard full sheets. The sets cut for sofa beds are ranked in the best sleeper sofa sheets.

What size is a full futon mattress?

75 by 54 inches, the same plan as a standard full mattress, with depth ranging from six to eight inches. That is why standard full sheets fit, and why a twin mattress will not fit a full futon frame.

How thick can a sleeper sofa mattress be?

About 4.5 inches for most fold-out frames, because the mattress has to fold into a cavity. A bi-fold futon frame takes eight inches, a tri-fold about six, and a trundle drawer six or less. Measure the cavity in your own sofa rather than the mattress currently in it, which has compressed.

Is a cabinet bed really a queen?

Check the measured mattress. The Arason Creden-ZzZ is sold as a queen cabinet bed and its included tri-fold is a sleeping surface Arason does not publish, which is essentially a full. The Night & Day Cube's optional mattress is 80 by 63 by 6 inches, much closer to a genuine queen.

Sources

Keep reading

The full size reference

Convertible sofas do not have a size at all

Depth limits by frame, which matter as much as plan size

What bedding actually fits what

How to measure the frame you already have

Replacements in the sizes that exist

Milliard 4.5 Inch Memory Foam Sleeper Sofa Replacement Mattress (Full)

Royal Sleep Products 10 Inch Pocket Coil Futon Mattress (Full)

Milliard 6-Inch Tri-Fold Memory Foam Mattress (Twin XL)

Zinus 8 Inch Green Tea Memory Foam Mattress (Twin)

Common questions

Related on Fold & Futon