A split sheet for an adjustable bed

Short answer: A split sheet has an opening in the middle so the mattress can bend without the sheet pulling tight. Without it the sheet contracts every time the bed is raised.

Why an ordinary sheet does not work

When the head end is raised, the distance across the mattress gets shorter on top and longer underneath. A sheet with no split cannot follow that movement and pings off the corners.

How a split sheet is built

There is an opening or split running crosswise, typically with elastic at each end. The two halves can move independently of each other. See bamboo split sheets.

How to choose a size

Measure the mattress length, width and depth as for an ordinary sheet. Also check that the position of the split matches the bed's hinge point. See bamboo sheets and bamboo bedding.

Frequently asked questions

Can you use two ordinary sheets instead

That works on a divided bed, but not on a single mattress.

Where does the split usually sit

At the transition between back and seat, about a third of the way down.

Are they more expensive

Often slightly, because there is more sewing in them.