The ideal thread count for any sheet is between 300 and 500, as this will give you a high-quality and soft sheet at a fair price. However, while all sheets need to be soft on an adjustable bed, they need to be extra strong too.
That means not only will you want a thread count between 300 and 500, but you’ll also want to look for durable fabrics that will stand up to multiple adjustments without ripping or wrinkling too much. Cotton, polyester, and linen are all sturdy fabrics that will make excellent sheets for an adjustable bed.