ChartStandard dimensions — nothing to enter.
A Twin XL mattress is 38 × 80 inches — 3 ft 2 in wide by 6 ft 8 in long, or 97 × 203 cm. It needs a room of at least 8 × 9 ft.
| Measurement | Size | Metric or area |
|---|---|---|
| Width | 38 in | 97 cm |
| Length | 80 in | 203 cm |
| In feet | 3 ft 2 in × 6 ft 8 in | — |
| Sleeping surface | 21.1 sq ft | — |
| Smallest room it fits | 8 × 9 ft | 72 sq ft |
| Comfortable room | 10 × 10 ft | 100 sq ft |
| Fitted sheet | 38–39 × 80 in | typical range |
| Flat sheet | 66–68 × 102 in | typical range |
| Comforter or duvet | 68 × 90 in | typical range |
| Pillows | 1 standard (20 × 26 in) | — |
| Rug under the bed | 5 × 8 ft | — |
Room sizes assume 24 in of clear floor down each side and at the foot as a minimum, 36 in to be comfortable. Bedding is not standardized the way mattresses are. Mattress dimensions are fixed, but sheet and comforter cuts vary between manufacturers, so these are the common US retail ranges — check the size on the packaging of the set you are buying.
The mattress itself. A Twin XL is 38 × 80 inches — 3 ft 2 in wide by 6 ft 8 in long, or 97 × 203 cm. It is also sold as a Single XL. A twin with five extra inches of length. The standard mattress in US college dorms, and the half that makes a split king.
The room it needs. Bed dimensions are only half the question; the floor around the bed is the other half. The rule used across this site is 24 in of clear floor down each side and 24 in at the foot as the minimum you can live with, and 36 in as the figure that fits a nightstand and lets two people pass. For a Twin XL that is 8 × 9 ft at minimum and 10 × 10 ft to be comfortable. Those are the same numbers the mattress size chart uses, because both come from the one rule.
Bedding, and why these are ranges. The fitted sheet is cut to the mattress, so a Twin XL fitted sheet runs 38–39 × 80 in. Everything else is deliberately larger: the flat sheet at 66–68 × 102 in and the comforter at 68 × 90 in have to hang over the sides and the foot, which is why a comforter bought to the mattress size always looks too small on the bed. Bedding is not standardized the way mattresses are. Mattress dimensions are fixed, but sheet and comforter cuts vary between manufacturers, so these are the common US retail ranges — check the size on the packaging of the set you are buying.
How it compares. A Twin XL is 5 in longer than a Twin (38 × 80 in against 38 × 75 in). A Twin XL is 16 in narrower and 5 in longer than a Full (38 × 80 in against 54 × 75 in). Full dimensions for every size sit on the mattress size chart.
Pocket depth still matters. These dimensions describe the mattress footprint, not its height. A fitted sheet also has to clear the mattress depth plus any topper, which is the measurement most often got wrong — the bedding size chart covers the depth bands.
A Twin XL mattress is 38 × 80 inches, which is 3 ft 2 in wide by 6 ft 8 in long. In centimeters that is 97 × 203 cm.
A 8 × 9 ft room (72 sq ft) is the smallest that leaves 24 in down each side and 24 in at the foot. 10 × 10 ft (100 sq ft) is where it stops feeling tight and a nightstand fits on both sides.
It is built for a tall single sleeper. Split across two sleepers, a Twin XL gives each person 19 in of width — a single bed is 38 in for comparison.
Fitted sheet 38–39 × 80 in, flat sheet 66–68 × 102 in, comforter or duvet 68 × 90 in, and 1 standard (20 × 26 in). These are ranges rather than one number because bedding cuts vary by manufacturer, unlike the mattress itself. Sheets are sold by bed name, so buying "Twin XL" is right — the mattress depth is the measurement worth checking on the packaging.
A Twin XL is 5 in longer than a Twin (38 × 80 in against 38 × 75 in). The Twin XL needs a bigger room for it: 8 × 9 ft against 8 × 9 ft.
A 5 × 8 ft rug is the size that works in most rooms — it carries the bed and still shows floor on all three walking sides. The exact answer depends on your room, which is what the rug size calculator works out.