ChartStandard dimensions — nothing to enter.
King bedding is not one size. The fitted sheet matches the mattress at 76–78 × 80 in, the flat sheet is 108 × 102 in and the comforter is 102–108 × 90–94 in — each is cut for a different job.
| Piece | Size | Why that size |
|---|---|---|
| Fitted sheet | 76–78 × 80 in | Matches the mattress exactly and grips underneath |
| Flat sheet | 108 × 102 in | Wide enough to tuck on both sides and the foot |
| Comforter or duvet | 102–108 × 90–94 in | Hangs over the sides so the bed looks made |
| Duvet cover | 102–108 × 90–94 in | Cut to the comforter, not to the mattress |
| Pillows | 2 king (20 × 36 in) | Sized to sit across the 76 in width |
| Mattress | 76 × 80 in | The measurement everything else is derived from |
Every piece except the fitted sheet is deliberately bigger than the mattress — that overhang is the whole design. 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.
Start from the mattress. A King mattress is 76 × 80 inches (193 × 203 cm), and the fitted sheet is cut to match at 76–78 × 80 in. Everything else on the bed is sized off that footprint, which is why bedding is sold by bed name and not by inches.
The flat sheet is wider on purpose. At 108 × 102 in it carries roughly 16 in of tuck down each side. Buy one cut to the mattress width and it pulls out every night — the extra fabric is doing a job.
Why every figure here is a range. 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 comforter is wider still. 102–108 × 90–94 in lets the cover hang over the sides of the mattress rather than stopping at the edge. On a bed with a thick mattress or a topper, size up rather than down: a comforter that stops short reads as too small from across the room, and no amount of arranging hides it.
Depth is the measurement that goes wrong. The footprint of a fitted sheet is fixed by the size name, but the pocket depth is not. Standard pockets take a mattress up to 14 in, deep pockets 15 to 18 in, extra-deep above that — and a topper counts towards the total. The bedding size chart covers the bands.
The room the bed sits in. If you are still choosing the bed rather than the sheets, a King needs at least 11 × 9 ft of floor. The King bed size page has the dimensions and clearances in full.
Fitted sheet 76–78 × 80 in, flat sheet 108 × 102 in, comforter or duvet 102–108 × 90–94 in, and 2 king (20 × 36 in). The mattress underneath is 76 × 80 in.
No, and it should not be. The mattress is 76 × 80 in and the comforter is 102–108 × 90–94 in so that it hangs over the sides. Matching the two exactly leaves the bed looking undressed.
Only if the pocket depth allows it. The 76–78 × 80 in footprint is fixed, but pockets run from 14 in standard up to 22 in extra-deep. Measure the mattress from the seam at the top to the seam at the bottom, add any topper, and buy to that.
2 king (20 × 36 in). That is what sits across the 76 in width without crowding or leaving a gap.
Yes — a duvet cover is cut to the comforter it holds, so both are 102–108 × 90–94 in for a King. Neither is cut to the mattress.
The flat sheet and comforter have some tolerance because they are meant to overhang. The fitted sheet does not: it is cut to 76–78 × 80 in and will either not reach or will not stay on.