Duvet covers are sized to the insert inside them, not to the mattress. A cover that is smaller than the insert will not zip; one that is much larger sags at the edges. Measuring takes two minutes and saves a return.
The four sizes
| Cover | Width × length | Fits an insert about |
|---|---|---|
| Twin | 68 × 88 in | 68 × 86 to 68 × 88 in |
| Twin XL | 68 × 92 in | 68 × 90 to 68 × 92 in |
| Queen | 88 × 88 in | 86 × 86 to 88 × 88 in |
| King | 104 × 88 in | 102 × 86 to 104 × 88 in |
These are the print partner's stated measurements. Pre-made covers can vary by up to 3 inches in either direction, so treat the numbers as the center of a range.
How to measure
- Lay the insert flat on the bed or the floor.
- Measure the short side. That is the width.
- Measure the long side. That is the length.
- Pick the cover that matches, or is up to 2 inches bigger in each direction.
If the insert has a label, the label size is a good first clue, but labels round generously. The tape measure wins.
Twin or Twin XL
Both are 68 inches wide; Twin XL is 4 inches longer. Dorm beds and most extra-long twin mattresses use Twin XL inserts. If your insert measures closer to 90 inches long than 86, order Twin XL.
Full or double inserts
There is no Full cover. Full inserts usually run 80 to 86 inches wide, and the Queen cover at 88 inches is the closest fit. Expect it to sit slightly loose; a pair of clip-on duvet grips keeps the insert from drifting.
If you are between sizes
Go up. A slightly loose cover looks like bedding; a tight one looks like a pillowcase and strains the zipper. The size and care guide repeats the table and adds the wash instructions, and the returns page explains what happens if a size does not work out.