The sheet slides off the mattress

Short answer: A sheet slides when it is too big or lacks elastic all the way round. Measure the mattress depth and choose a fitted sheet with elastic in the whole edge.

Depth is the overlooked measurement

Most people choose sheets by width and length and forget depth. A mattress of twenty five centimetres needs a sheet with at least the same corner depth. If the depth is too shallow, the sheet only grips the edge and comes off at the first turn.

Elastic all the way round

A sheet with elastic only in the corners slides far more easily than one with elastic in the full edge. It is the single detail that decides most whether the sheet survives the night. See bamboo fitted sheets.

When the mattress is smooth

A mattress with a smooth cover gives the sheet nothing to hold onto. A thin under sheet or a textured mattress protector underneath solves it without changing anything else. See bamboo sheets.

Adjustable beds need something else

With an adjustable bed the sheet has to follow the bend. A split sheet or an envelope sheet stays put where an ordinary sheet is pulled off. See bamboo split sheets and bamboo envelope sheets.

Frequently asked questions

Can an oversized sheet be tightened

You can sew elastic into the corners, but it never works as well as the right size.

Do sheet grippers help

Yes, they hold a slightly oversized sheet. They will not rescue a sheet with too shallow corners.

Do sheets shrink in the wash

A little at the first wash. Never buy a sheet that only just fits in depth.