Short answer: a full mattress is 54 inches wide by 75 inches long, which is 137 by 191 centimeters. Full and double are two names for the same size, sold as full in the US and double in most other markets. There is no difference between them.
The number that matters more than the width is the length. At 75 inches, a full is five inches shorter than every larger size, and that is what catches people out.
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The dimensions, and what sits either side
| Size | Inches | Centimeters | Difference from full |
|---|---|---|---|
| Twin | 38 x 75 | 97 x 191 | 16 in narrower, same length |
| Twin XL | 38 x 80 | 97 x 203 | 16 in narrower, 5 in longer |
| Full (double) | 54 x 75 | 137 x 191 | — |
| Full XL | 54 x 80 | 137 x 203 | Same width, 5 in longer |
| Queen | 60 x 80 | 152 x 203 | 6 in wider, 5 in longer |
| King | 76 x 80 | 193 x 203 | 22 in wider, 5 in longer |
The 75 inch problem
Seventy five inches is 6 ft 3. Allow for a pillow and for the fact that nobody sleeps with their heels at the exact edge, and a full comfortably takes a sleeper up to about 5 ft 10. Above that your feet are at the end of the mattress, and above 6 ft they are off it.
This is the single most useful thing to know about the size, and it is why twin XL exists at 80 inches for a single sleeper who is tall. Every size above full is 80 inches or more, so a full is the last stop before length stops being an issue.
If you want full width and queen length, the size is a full XL at 54 by 80 inches. It is uncommon, mattresses are available and bedding is harder to find, and it is the right answer for a tall single sleeper in a room that cannot take a queen.
Who a full suits
- One adult under about 5 ft 10 who wants room to spread out. This is the size at its best: 54 inches to one person is generous.
- A teenager’s room, where a twin has been outgrown and a queen will not fit.
- A guest room used occasionally, where two people share for a few nights at a time.
- A room under about 10 by 10 feet, where a queen leaves no walking space.
Who it does not
- Two adults every night. A full gives each person 27 inches, which is less than a twin bed gives one child. The full comparison is in full vs queen.
- Anyone over about 5 ft 10, unless you can find a full XL.
- Anyone planning an adjustable base. Bases are made in twin XL, queen, king and split king. Full is the size the category skips, which matters if you are considering the setup in choosing an adjustable base.
The room it needs
A full works in a 9 by 10 foot room and is comfortable in a 10 by 12. Allow 24 to 30 inches of walking space on each side you use, and 36 inches in front of anything with drawers. Against a wall you only need clearance on three sides, which is what makes a full fit rooms a queen cannot.
Bed height is a separate question the size chart never covers. Frame plus foundation plus mattress should put the sleep surface somewhere near knee height, 24 to 26 inches for most adults, and that arithmetic is in platform bed vs box spring.
Bedding and accessories
Full bedding is widely available and there is less of it than in queen, which is worth knowing before you fall for a sheet set. Two specific points: fitted sheet pocket depth has to clear your mattress plus any topper, as we set out in choosing sheets, and a full duvet is often sold as full or queen in one size, which fits a full generously.
What to buy in a full
- Medium firm hybrid, the safe default: the Vesgantti medium firm hybrid, sold in full among other sizes.
- Memory foam: the Novilla Bliss gel memory foam. Which construction suits you is in memory foam vs hybrid.
- Spare room, thinner and firmer: the EGOHOME 10 inch memory foam, which is the right trade for a bed used a few nights a year.
- Support underneath: the Zinus bunkie board if your frame has wide slats, and whether you need a foundation at all is in do you need a box spring.
Common questions
What size is a full mattress? 54 inches wide by 75 inches long, or 137 by 191 centimeters.
Is a full the same as a double? Yes. Two names for one size, full in the US and double elsewhere. Neither is bigger.
How tall can you be for a full bed? Comfortably up to about 5 ft 10. At 75 inches long, a full is five inches shorter than a queen, and anyone near 6 ft will find their feet at the edge.
Is a full big enough for two people? For occasional use, yes, at 27 inches each. As a nightly arrangement for two adults it is the size most couples move away from.
What is a full XL? A full at queen length, 54 by 80 inches. Uncommon in stores, useful for a tall single sleeper in a small room, and harder to buy bedding for.
The bottom line
54 by 75 inches, the same thing as a double, and the length is the number to check before the width. Under 5 ft 10 and sleeping alone, a full is a generous bed. Over that, or sharing every night, the size above is the one to look at.
