Bed sizes and dimensions: the chart, and where it stops being reliable

Every US bed size, in inches, feet and centimetres

Read the dimensions column rather than the names. The names are the part that misleads, and the next section shows why.

Twin bed dimensions

A twin bed is 38 by 75 inches. That is 3 ft 2 in by 6 ft 3 in, or 96.5 by 190.5 centimetres, and it covers 2,850 square inches, which is 19.8 square feet of floor.

Two things about that figure are worth knowing before you buy for the space rather than the sleeper. A twin is the narrowest bed on this chart, but it is not the shortest: it shares its 75 inch length exactly with a full. Anyone whose feet reach the end of a twin gains nothing from a full and needs the extra five inches of a twin XL instead.

The second is that the width is the number that stays fixed. A twin and a twin XL are both 38 inches across, so neither buys you room across the bed, and the length is the only thing you are choosing between.

The kids mattresses we reviewed publish the same three figures for their twin, twin XL and full, so the child sizes are the adult sizes rather than a smaller set of their own: see our kids mattress review for the beds themselves.

Queen bed dimensions

A queen bed is 60 by 80 inches. In feet that is exactly 5 ft by 6 ft 8 in, in centimetres 152.4 by 203.2, and the sleeping surface is 4,800 square inches or 33.3 square feet.

The 80 inch length is the number to hold on to, because a queen, a king and a twin XL all share it. Moving from a queen to a king adds 16 inches of width and no length at all, which is why the change affects how wide your sheets need to be and not how long.

A split queen is the same footprint in two halves. Each half is 30 by 80 inches, and 30 twice is 60, so two of them come to a queen to the inch, in the same way two twin XLs come to a king.

One caveat worth stating plainly, because it is the usual reason a measurement comes out wrong: the dimensions of a queen size bed given here are the mattress. A frame sits around it and adds its own width and length, so measure the frame you own before you measure the wall.

Why the names mislead: three lengths, not six

Six size names imply six steps up a ladder. Sort them by their published numbers and the ladder turns out to be a grid with only three rungs of length.

• 75 inches long: twin and full.
• 80 inches long: twin XL, queen and king.
• 84 inches long: California king.

Three of the six most common beds are exactly the same length, which is why a queen, a king and a twin XL all take 80 inch bedding lengths, and why "going up a size" from a queen to a king does nothing at all for a tall sleeper.

Width has five values rather than two, so width is where the range actually moves: 38, 54, 60, 72 and 76 inches. Two consequences follow, and both are the sort of thing people discover after buying:

• If you need length, the range gives you two chances. Twin to twin XL adds five inches, and king to California king adds four. Nothing else in the list is longer than 80 inches.
• Two of the moves are trades, not upgrades. Twin XL to full gains width and gives up length. King to California king gains length and gives up width. In both cases the size that sounds bigger is smaller in one direction.

Where two published charts disagree

Every size chart on the internet, including the one above, is copied from somewhere. We can only publish what we checked, so we checked a second one: the size charts Sleepyhead publishes for its mattress toppers, read 14 July 2026. Both companies sell into the same six size names. They do not fully agree.

Three departures, and they are different in kind:

• Full is 54 inches on one chart and 53 on the other. One inch, on the one size out of six where the two lists differ at all.
• One chart has a size the other does not. Full XL, 53 by 80 inches, appears on the topper chart and does not appear in the nine row mattress chart at all. A size can exist for one company and not another.
• California king appears on one chart and not the other. The topper range stops at king. The longest bed in the convention has no topper in that particular line, which is a stocking decision rather than a measurement, but it is the sort of gap a size chart never warns you about.

What we are not claiming. We did not put a tape measure on either product, so this is a disagreement between two published charts and not a finding about two objects. A topper is also not a mattress, and a maker could reasonably cut a topper slightly narrow so it sits inside a fitted sheet rather than fighting it.

The reason we do not think that explains this one: the same topper charts match the mattress chart exactly on twin, twin XL, queen and king. A deliberate undersizing policy would show up on every size, not on full alone. That is our reasoning from the published figures, not something either company told us.

The practical version is short. A size name is a shopping category, not a measurement. If a listing states its own dimensions, buy against those. If it does not, the size name is an assumption you are making on the maker's behalf, and an inch is enough to matter on anything that has to grip, which is exactly how fitted sheets fail on the wrong bed.

Twin against twin XL

Same width, five inches of length apart: a twin is 38 by 75 inches, a twin XL is 38 by 80. This is the cleanest comparison in the whole range, because only one number changes.

Those five inches decide three things. Bedding is not interchangeable, since a fitted sheet cut for 75 inches cannot reach the corners of an 80 inch bed, and one cut for 80 sits slack on a 75. The twin XL is the size student accommodation standardised on, which is why it is easy to find bedding for it in August and harder in other months.

And two twin XLs side by side come to 76 by 80 inches, which is a king to the inch. That is not a coincidence, it is what a split king is: a king footprint made of two separately adjustable halves, which is why adjustable bases are sold that way.

Neither is the "bigger" bed in any sense that matters for a room. They occupy the same 38 inches of wall width. If your problem is that your feet reach the end of the bed, the twin XL is the answer and the full is not, because a full is no longer than a twin.

Twin XL against full

A twin XL is 38 by 80 inches and a full is 54 by 75. The full is sixteen inches wider and five inches shorter, so this is a trade rather than a step up, and which one is "bigger" depends entirely on which direction you need.

By our arithmetic from those published figures, a twin XL covers 3,040 square inches and a full 4,050, so the full is the larger bed by about a third in area while the twin XL is the longer one by five inches. For a tall single sleeper that makes the full a downgrade dressed as an upgrade.

For someone who sprawls, or who shares occasionally, the full is the obvious pick and the extra width is worth more than the length. A full is also the widest bed that still fits most rooms that took a single, which is usually the real constraint.

If neither works, the size that solves both at once is a queen, at 60 by 80: full width plus, and twin XL length. That is the step where the range stops trading and starts adding.

King against California king

A king is 76 by 80 inches and a California king is 72 by 84. The California king is four inches narrower and four inches longer, so the two are not a size step but the same rectangle turned: a king for width, a California king for height of sleeper or for a long narrow room.

By our arithmetic the trade is not quite even. A king covers 6,080 square inches and a California king 6,048, so the king is the larger bed by 32 square inches even though the California king is the longer one. The gap is small enough to ignore when choosing and large enough to settle which name means bigger.

That swap has a consequence sharp enough to deserve its own page, because it is the most commonly attempted and most reliably failed substitution in bedding, and the arithmetic of why is not obvious. Rather than repeat it here: king sheets on a California king, and why the four inch swap fails.

The dimension no size chart gives you

Every chart on this page gives length and width. None gives height, and height is the measurement that decides whether bedding fits, because a fitted sheet has to reach down the side of the mattress and back underneath it.

Height is also the one dimension you can change after buying the bed. A mattress has a height, and then a topper adds two to four inches to it, and a protector adds a little more. That total is what a sheet has to clear, which is why a sheet can be the correct size and still not stay on.

The two measurements are bought separately and neither substitutes for the other: size decides which bed the sheet is cut for, and pocket depth decides whether it reaches under the stack you have actually built.

If you are working out which size to buy in the first place, the size is the easy half of that decision and the construction is the hard half.

Our mattress comparisons cover the beds we have verified, what a hybrid actually is covers the choice between a coil core and a solid one, and mattress toppers are the cheaper way to change how a bed you already own feels without changing its footprint at all.

Common questions