A Murphy bed cabinet sits 15–20 inches deep against the wall when closed, and swings out to a floor projection of roughly 82–90 inches when open — that is the mattress length plus the lift mechanism. Cabinet width tracks the mattress, from about 44 inches for a twin to 84–92 inches for a king, and most cabinets stand 84–92 inches tall. The number people forget is the walk space in front: budget another 30 inches beyond the open bed so you can actually get in and make it.
WALL
15–20 in closed depth
mattress folded down (open)
82–90 in floor projection
30+ in walk
Murphy bed dimensions by mattress size
Sizes vary by brand and by whether the cabinet is a bare frame or a full built-in with side towers, but the ranges below cover almost every vertical wall bed sold in the US. Widths are the cabinet, not the mattress, so they already include the frame and side stiles.
| Mattress | Cabinet width | Cabinet height | Closed depth | Open floor projection |
|---|---|---|---|---|
| Twin (38 × 75) | 42–46 in | 84–88 in | 15–17 in | ~82 in |
| Twin XL (38 × 80) | 42–46 in | 88–92 in | 15–17 in | ~86 in |
| Full (54 × 75) | 58–64 in | 84–88 in | 16–18 in | ~82 in |
| Queen (60 × 80) | 64–70 in | 88–92 in | 16–18 in | ~88 in |
| King (76 × 80) | 84–92 in | 88–92 in | 18–20 in | ~90 in |
What to Look For When Buying a Murphy Bed
A wall bed is a big purchase, so weigh the mechanism and build before size.
- Lift mechanism — a piston lift is smoother and safer than an old spring system
- Cabinet depth — confirm the closed depth fits your wall without blocking a walkway
- Mattress limit — most cap mattress thickness around 10 to 12 in
- DIY vs built-in — a hardware kit is cheaper; a built-in unit costs more but looks seamless
- Wall anchoring — a Murphy bed must anchor into wall studs to be safe
| Option | Typical US price | Best for |
|---|---|---|
| DIY hardware kit | $300–700 | Budget builders |
| Freestanding cabinet bed | $1,500–3,000 | Renters, no install |
| Built-in wall bed | $2,000–5,000 | Seamless look |
Prices are typical US ranges and vary by size, material, and brand — ballparks, not quotes.
One spec that catches buyers out is mattress thickness. Most vertical lift mechanisms are rated for a 10–12 inch mattress and no thicker, so a plush 14-inch hybrid can jam the fold or overload the pistons — check the maximum mattress depth on the spec sheet before you plan to reuse a mattress you already own.
If you are still deciding between mattress sizes before you shop a cabinet, our bed size calculator and the full bed and mattress size guide pin down the mattress footprint first — the cabinet is built around that number.
Closed depth is where people get surprised
Loaded with bedding, a cabinet rated at 16 inches often sits at 18 or 19. Everyone fixates on the open bed and forgets that the cabinet lives in the room 23 hours a day. A quality vertical wall bed closes to 15–18 inches deep — genuinely slim, shallower than most bookshelves.
The catch is bedding. Pillows and a thick comforter add real bulk, so that rated 16-inch cabinet can bulge past 18 once it is loaded, and cheap piston mechanisms push it out further. If you are lining the closed bed up with an adjacent 24-inch closet or a desk return, that extra inch or two decides whether the doors sit flush.
Deep cabinets (18–20 in) usually pack an integrated mattress retainer bar or a built-in gas-strut housing, which is what lets you leave sheets and a low-profile comforter on the bed when it folds up. That convenience costs you depth, so measure the wall it lands on and subtract baseboard thickness — a 3/4-inch base trim quietly steals depth clearance at the floor.
How much floor you actually need to open it
Plan for the open bed plus at least 30 inches of walkway. Floor projection is the whole game in a small room. A queen wall bed reaches about 88 inches from the wall when down — call it 7 feet 4 inches — and you cannot stop there.
You need clearance to stand at the foot and walk the sides, so that 30-inch buffer is not optional. It puts the practical clearance at roughly 10 feet of open floor from the wall for a queen, and a bit less for a twin or full.
Cabinet width by mattress size
Twin
42–46 in
Full
58–64 in
Queen
64–70 in
King
84–92 in
Cabinet width includes frame and side stiles — add side towers separately.
Rugs are the sneaky mistake here. People center a rug where the closed cabinet sits, then the bed folds down on top of it and the front legs crush the pile or catch the edge. If you want a rug in the room, size and place it for the open bed footprint, not the closed one — the rug size under a bed guide covers where the legs should land.
Vertical vs horizontal: which orientation fits your ceiling
A standard vertical wall bed needs 84–92 inches of ceiling height, which is fine for an 8-foot room but tight under a sloped attic ceiling or a basement with 7-foot clearance. That is where a horizontal, side-mounting wall bed earns its keep: the mattress folds sideways, so the cabinet is only about 50–60 inches tall for a full or queen.
You trade ceiling height for wall width — a horizontal queen wants roughly 84 inches of wall run instead of 70. Horizontal beds are usually offered up to queen; kings are vertical only.
- Tall room, narrow wall: go vertical — it uses less wall and more height.
- Low ceiling or under the stairs: go horizontal — it stays under 60 inches tall.
- Torn between a wall bed and a fixed frame: compare the footprint against bunk bed dimensions before you commit.
Wall width, ceiling height, and side clearance
The cabinet width in the table is the bare bed. Add a desk return, side towers, or a bookcase and the whole assembly can span 9–12 feet. This is exactly why wall beds show up in home offices — a queen that folds flat behind a desk lets one room do double duty. If that is your plan, lay it out alongside the home office setup guide so the desk depth and the closed cabinet do not fight for the same 30 inches of floor.
Leave 1–2 inches of side clearance for the cabinet doors and hardware, and confirm your ceiling with the actual open height, not the nominal room height — crown molding and a dropped soffit both steal from the top.
One detail installers wish buyers thought about sooner is power. A wall bed usually covers the outlet behind it, so plan a surface-mounted strip or a side-tower outlet for reading lights and a phone charger before the cabinet goes up. In a genuinely small footprint, sanity-check the whole layout against bed size for a 12×12 room and, if it is a spare-room conversion, the guest room size minimums so the open bed does not block the door swing.
Before you buy: measure these three numbers
Get these three and the spec sheet tells you the rest:
- Wall width at the exact mounting spot, not the widest part of the room.
- Ceiling height minus any crown molding or soffit.
- Floor depth from the wall to the nearest obstruction — door swing, closet, or radiator.
The most common regret is not the closed cabinet — it is discovering the open bed lands 6 inches into a doorway or a closet swing.
Frequently Asked Questions
Almost always, yes. A vertical wall bed is top-heavy and the mechanism stores real spring or piston tension, so it must be anchored to wall studs (or a floor cleat on some models) to keep it from tipping when you open it. Anchoring into drywall alone is unsafe — find the studs and use the hardware the manufacturer supplies.
On many models, yes. Beds with an integrated mattress retainer strap or bar hold sheets and a thin comforter in place as the bed folds up. Thick duvets and extra pillows will not fit, and they add depth — expect the closed cabinet to sit an inch or two deeper than its rated 15–18 inches.
The mechanism does the work, so day to day one adult can lower and raise it with light effort — gas-piston systems are the easiest. The cabinet itself is heavy to install, often 150–300 pounds assembled for a queen, which is a two-person, sometimes three-person job to mount.
Plan on the wall width for your mattress plus a room depth of about 10 feet, so the open queen (roughly 88 in) still leaves a walkway. A twin fits tighter spaces, but confirm the mattress footprint against a spec sheet before you shop cabinets.