Murphy bed sizes — Twin, full, queen and king against the same wall
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Murphy bed sizes are simply US mattress sizes, because the mattress is the one thing the manufacturer cannot change. Twin, full, queen and king are fixed dimensions, and everything about the cabinet — how tall it stands, how much wall it eats, how much floor has to stay clear — follows arithmetically from them.
Which means you can work out whether a size fits your room before you look at a single product. That is the whole purpose of this page.
The four mattresses are twin 38 × 75, full 54 × 75, queen 60 × 80 and king 76 × 80 inches. For a vertical wall bed: the wall run you need is the mattress width plus cabinet sides, the clear floor is the mattress length, and the closed height is roughly the mattress length. So a queen needs about 60 inches of wall, 80 inches of permanently clear floor, and 80 inches of height. Side-mounting swaps the height and wall figures. Full and twin are both only 75 long — five inches less than queen — which is often what decides a tight room.
The four sizes side by side
| Size | Mattress | Wall needed | Clear floor | Closed height |
|---|---|---|---|---|
| Twin | 38 × 75 in | Over 38 in | 75 in | About 75 in |
| Full (double) | 54 × 75 in | Over 54 in | 75 in | About 75 in |
| Queen | 60 × 80 in | Over 60 in | 80 in | About 80 in |
| King | 76 × 80 in | Over 76 in | 80 in | About 80 in |
Those are mattress dimensions. Every real cabinet adds material around the mattress — usually two to four inches on each side and a few at the top — so treat the table as the minimum and the listing as the truth.
Two rows in that table do most of the work. Twin and full are both 75 inches long, and queen and king are both 80. The length changes once, between full and queen, and that five-inch step is the single most useful fact on this page.
Where the five inches decide it
Picture a small bedroom with a fitted wardrobe, a radiator or a doorway 76 inches out from the wall you want to use. A queen is out. A full fits, and it is 54 inches wide, which is only six inches narrower than the queen you wanted.
People shopping by width alone never find this, because they compare 60 against 54 and conclude the full is a compromise. In a length-constrained room it is not a compromise at all; it is the largest bed that works.
The reverse case exists too. A long narrow room with 90 inches of floor but only 50 inches of clear wall cannot take a full — there the answer is a twin, and no amount of shopping changes it.
What each size is actually for
Twin
A child’s room, a home office that occasionally sleeps someone, a narrow box room. It needs the least wall of any size, which is usually why it gets chosen. At 38 inches wide it is a single bed and nothing more.
Full
A generous single or an occasional double. Two adults get 27 inches each, which is narrower than a standard single bed. Excellent for a teenager, excellent for one adult who spreads out, adequate for guests a few nights a year.
Queen
The default, and the size with the most models and the best prices. Two adults get 30 inches each, which is the normal expectation of a double bed in the US. If your room takes a queen, this is where to start.
King
Two adults with room to spare, at the cost of seven feet of uninterrupted wall and a substantially higher price. The king is where the mechanism gets heavier and the model choice thins out.
How side-mounting changes the table
A side-mount pivots on the mattress’s long edge instead of its short one, so the closed cabinet is as tall as the mattress is wide and as long as the mattress is long. The two numbers swap.
| Size | Vertical: height × wall | Side-mount: height × wall |
|---|---|---|
| Twin | 75 in tall, 38 in wall | 38 in tall, 75 in wall |
| Full | 75 in tall, 54 in wall | 54 in tall, 75 in wall |
| Queen | 80 in tall, 60 in wall | 60 in tall, 80 in wall |
| King | 80 in tall, 76 in wall | 76 in tall, 80 in wall |
Read down the right column and the pattern is clear: the smaller the mattress, the more side-mounting gains you. A twin drops from 75 inches tall to 38. A king drops from 80 to 76, which is worth nothing. That is why the horizontal twin is the lowest-ceiling option in the whole category and a horizontal king is a curiosity. The mechanism itself is explained in side-mount Murphy beds.
What the table does not tell you
Three things sit outside the arithmetic and catch people out regardless of size.
- The mattress thickness limit. Every cabinet states a maximum, because the mattress folds into the case with the bedding on it. This is independent of size and it is the most common reason a newly installed bed will not close. Buy the cabinet, read the number, then buy the mattress.
- Swing clearance. The closed height is not the whole ceiling requirement on a vertical mount — the bed arcs through a taller path as it comes down. Listings state it; check it rather than assuming.
- Usable wall, not total wall. A light switch, a door swing or a window reveal at the edge of the run removes that width as effectively as a solid obstruction.
Sizes that are not on the table
Twin XL is 38 × 80 — same width as a twin, same length as a queen. Rare in Murphy beds, and worth knowing about because it needs queen-length floor with twin-width wall.
California king is 72 × 84: narrower than a standard king and four inches longer. Very few wall beds are made for it, and a standard king cabinet will not take one.
Full XL (54 × 80) barely exists in this category. If a listing claims it, read the actual figures rather than the label.
Size and cabinet material
The bigger the mattress, the more load goes into the points where the mechanism bolts to the case, and the further the cabinet has to span without sagging. A panel that behaves perfectly well on a twin is working much harder on a king.
Solid timber and plywood hold a screw indefinitely; particleboard enlarges its hole and cannot be repaired well. Most cabinets use engineered panel somewhere, which is fine when the load points are reinforced — the vocabulary on the listing is decoded in what engineered wood actually is.
Measure before you shop
- Tape measure Wall run between obstructions, clear floor, then ceiling — in that order
- Stud finder Every size needs studs; only the number of them changes
- Spirit level Plumb decides how the bed folds for the rest of its life
- Mattress retention strap Ships with most cabinets; check it matches your mattress depth
What to buy
Once the size is settled, go to the page for it: twin, full, queen or king. If no size fits the wall, the freestanding cabinet bed needs no wall at all, and the category as a whole is explained in how Murphy beds work.
Questions we get asked
What sizes do Murphy beds come in?
Twin, full, queen and king, matching standard US mattress sizes. Twin XL and California king exist but are rare, and full XL barely exists at all.
What is the most common Murphy bed size?
Queen. It has the widest model choice and the best prices, and 60 inches of wall is achievable in most rooms that have a spare wall at all.
How much room do you need for a Murphy bed?
Wall wider than the mattress, clear floor equal to the mattress length, and — on a vertical mount — ceiling above the closed height plus swing. A queen is about 60, 80 and 80 inches respectively.
Is a full Murphy bed the same as a double?
Yes. Full and double are two names for the same 54 × 75-inch mattress, and listings use both interchangeably.
Which Murphy bed size needs the lowest ceiling?
A horizontal twin, at about 38 inches closed. Among vertical mounts, twin and full are both about 75 inches — five less than queen or king.
Can I change the mattress size in an existing Murphy bed?
No. The cabinet, platform and mechanism are all built around one mattress size, and the lift is tuned to its weight. Changing size means changing the bed.
