Size charts
Mattress Size Chart: Every US Size in Inches and CM
Quick answer
The nine standard US mattress sizes, width by length in inches: Twin 38x75, Twin XL 38x80, Full 54x75, Full XL 54x80, Queen 60x80, King 76x80 and California King 72x84. Split King is two Twin XL mattresses (38x80 each) and Split California King is two 36x84 halves. Olympic Queen, Short Queen, Wyoming King, Texas King and Alaskan King are real sizes but are not industry-standard: dimensions vary by manufacturer.
Nine sizes are standardized across the US mattress industry: every major manufacturer cuts a Queen to the same 60 by 80 inches. Beyond those nine, a handful of specialty sizes exist for RVs, oversized rooms and multi-person beds, but they are not standardized, so the same name can mean a slightly different mattress from one brand to the next. The tables below separate the two groups instead of blending them.
On this page
What are the standard US mattress sizes?
| Size | Width (in) | Length (in) | Sleeps |
|---|---|---|---|
| Twin | 38 | 75 | 1 |
| Twin XL | 38 | 80 | 1 |
| Full (Double) | 54 | 75 | 2 |
| Full XL | 54 | 80 | 2 |
| Queen | 60 | 80 | 2 |
| King (Eastern King) | 76 | 80 | 2 |
| California King | 72 | 84 | 2 |
| Split King (two Twin XL mattresses) | 76 | 80 | 2 |
| Split California King (two 36 x 84 halves) | 72 | 84 | 2 |
Industry standard
These are standard published dimensions, the same across manufacturers.
Split King and Split California King rows show the overall footprint of the made-up bed. Each half is its own separate mattress, most often paired with a split adjustable base. See Split Size Decision Calculator.
Standard sizes converted to centimeters
| Size | Width (cm) | Length (cm) |
|---|---|---|
| Twin | 97 | 191 |
| Twin XL | 97 | 203 |
| Full (Double) | 137 | 191 |
| Full XL | 137 | 203 |
| Queen | 152 | 203 |
| King (Eastern King) | 193 | 203 |
| California King | 183 | 213 |
| Split King half (Twin XL) | 97 | 203 |
| Split California King half | 91 | 213 |
Calculated
These figures are calculated from the numbers shown, not quoted from a manufacturer.
Centimeters are the inch figure multiplied by 2.54 and rounded to the nearest whole centimeter. Mattress and bedding listings outside the US round these the same way, so the numbers you find on a European sheet set should match.
Specialty sizes that are not industry-standard
| Size | Width (in) | Length (in) | Sleeps |
|---|---|---|---|
| Olympic Queen | 66 | 80 | 2 |
| Short Queen (RV) | 60 | 75 | 2 |
| Wyoming King | 84 | 84 | 2 |
| Texas King | 80 | 98 | 2 |
| Alaskan King | 108 | 108 | 3 |
Convention, not a standard
This is widely repeated guidance rather than a measured standard. Treat it as a starting point.
These are real products sold under these names, but no industry body sets their dimensions. A Wyoming King from one maker can run a few inches different from another. Confirm the exact dimensions on the listing before ordering sheets or a frame.
Why split sizes exist
A Split King is two Twin XL mattresses (38 by 80 inches each) placed side by side to form a King footprint. The point is not the seam down the middle, it is that each half can sit on its own adjustable base, so two sleepers can each set their own incline and firmness without disturbing the other. Split California King works the same way, with two 36 by 84 inch halves. If you are weighing a Split King against a single-piece King, run both through Split Size Decision Calculator and check base compatibility with Adjustable Base Compatibility Calculator.
Square footage of sleeping surface
| Size | Sq ft | Width per sleeper (in) |
|---|---|---|
| Twin | 19.8 | 38 |
| Twin XL | 21.1 | 38 |
| Full (Double) | 28.1 | 27 |
| Full XL | 30 | 27 |
| Queen | 33.3 | 30 |
| Olympic Queen | 36.7 | 33 |
| Short Queen (RV) | 31.3 | 30 |
| King (Eastern King) | 42.2 | 38 |
| California King | 42 | 36 |
| Wyoming King | 49 | 42 |
| Texas King | 54.4 | 40 |
| Alaskan King | 81 | 36 |
Calculated
These figures are calculated from the numbers shown, not quoted from a manufacturer.
Square footage is width times length divided by 144, rounded to one decimal. Width per sleeper divides the mattress width by how many people the size is meant to sleep, and is the number worth comparing when two sleepers keep waking up crowded on a Queen.
Shop mattresses by size
Zinus Memory Foam 8 Inch Green Tea Mattress
$109.998 inch twin memory foam.
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Zinus 12 Inch Twin XL Green Tea Memory Foam Mattress
$198.6712 inch twin xl memory foam, medium firm feel as the maker describes it.
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Zinus Memory Foam 12 Inch Green Tea Mattress
$239.9912 inch full memory foam.
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EGOHOME Queen Mattress 12 Inch
$249.9912 inch queen memory foam, medium firm feel as the maker describes it.
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EGOHOME King Size Memory Foam Mattress 12 Inch
$299.9912 inch king memory foam, medium firm feel as the maker describes it.
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Novilla California King Mattress
$265.9912 inch california king memory foam.
Check price on AmazonFrequently asked questions
What is the difference between a Queen and a King mattress?
A Queen is 60 by 80 inches. A King (Eastern King) is 76 by 80 inches, 16 inches wider than a Queen at the same length. That extra width is split between two sleepers, so each side of a King gets about 38 inches, close to a full Twin, versus about 30 inches per side on a Queen. Length is identical between the two, so a King does not help a tall sleeper, only a crowded one.
Is California King the same size as King?
No. California King is 72 by 84 inches: 4 inches narrower than a King (76 by 80) but 4 inches longer. King suits two sleepers who want maximum width. California King suits a taller sleeper or a narrower bedroom, since it is longer but takes up less width. Their total square footage comes out almost identical, at roughly 42 square feet, so the choice is about the shape of your room and your height, not extra space overall.
What size is a Full mattress?
A standard Full, also called a Double, is 54 by 75 inches. It is 6 inches wider than a Twin but the same length, and it is rated to sleep two, though each person only gets 27 inches of width, less than a Twin sleeper gets alone. A Full XL adds 5 inches of length, to 54 by 80, which matters for anyone over about 5 foot 10.
What is a Split King and why do people buy one?
A Split King is two separate 38 by 80 inch Twin XL mattresses placed together to form a King-sized footprint. Couples buy one so each side can run its own adjustable base, adjusting incline, firmness or massage settings independently without affecting the other sleeper. The tradeoff is a seam down the middle and the need for sheets sized or split for two mattresses rather than one.
Are Wyoming, Texas and Alaskan King mattresses standardized?
No. Unlike the nine standard US sizes, Wyoming King (84 by 84), Texas King (80 by 98) and Alaskan King (108 by 108) are not set by any industry body, so the exact inches can shift slightly between manufacturers using the same name. Always check the specific listing dimensions before ordering a frame, sheets or a room-fit calculation for one of these sizes.
How many square feet of sleeping surface does a Queen mattress have?
A Queen mattress is 60 by 80 inches, which works out to 33.3 square feet of sleeping surface. Split between two sleepers, that gives each person about 30 inches of width, noticeably less than the 38 inches each side gets on a King. Couples who feel crowded on a Queen are usually feeling that width difference rather than the mattress being undersized for one person.
How to read the numbers on this page. Standard mattress and bedding dimensions are industry-wide and the same across manufacturers. Guidance like replacement intervals, firmness by body weight and walking clearance is convention rather than a measured standard, and every table here says which it is. Where a manufacturer does not publish a figure we leave it out instead of estimating. This is not medical advice: a mattress is not a treatment for a medical condition, and persistent pain is a reason to see a clinician.