Split King Sheets for Adjustable Beds

Split king sheets for adjustable beds — a 5-piece set with two twin XL fitted sheets (one per side of the base), a full-width king flat sheet and two king pillowcases. Our split king sheets are 100% extra-long-staple cotton, 500 thread count sateen, single-ply, with 18 in. pockets rated for mattresses up to 18 in. deep including a 3 in. topper.

Why split king sheets exist

An adjustable king base is two independent halves, and a single king fitted sheet fights that from the first night: raise one head section and the sheet tugs across, untucks the other side, and both sleepers end up remaking the bed. Split king sheets for adjustable beds solve it structurally — two twin XL fitted sheets, one per half, each moving with its own mattress.

Specifications

• Fitted sheets: Two, each cut for 38 × 80 in. twin XL half
• Pocket depth: 18 in. — rated for mattresses up to 18 in. deep (mattress + topper combined)
• Elastic: Full-perimeter on each fitted sheet
• Flat sheet: Full king width, 110 × 108 in.
• Pillowcases: Two king cases, 20 × 40 in.
• Fiber: 100% extra-long-staple cotton
• Weave: Sateen, 500 thread count, single-ply
• Set contents: Five pieces total

Why 18 in. pockets matter on adjustable bases

Depth matters more on an adjustable base than on a flat one: the mattress flexes at the articulation points, and a shallow pocket pops loose at exactly the moment the base hinges. Our 18 in. pocket is rated for mattresses up to 18 in. deep, including a 3 in. topper — which covers the majority of memory-foam and hybrid mattresses used on adjustable frames.

Why the sateen weave suits an adjustable base

Fabric is chosen for enough give to move with the base rather than resist it. A very crisp, low-stretch weave is the wrong material for a bed that changes shape twice a night — it fights the articulation and puts stress on the elastic. Sateen has enough natural give to flex with the mattress; percale does not.

Split king sheets size guide

How to care for your split king sheets

• Machine wash warm, tumble dry low
• Fold each fitted sheet by seating the corners inside one another so the elastic keeps its shape
• Skip fabric softener — dulls the sateen luster and coats the elastic
• Iron on the reverse if a pressed finish is desired

Adjacent sizes — do not mix them up

Same set-up on a Cal king adjustable base? Cal king halves are 36 × 84 in. — narrower and longer than twin XL — and split king sheets will not cover them. Use our Split California King sheets instead. For a hospital or homecare bed, the size may be twin XL alone — see our Twin XL bed sheets or Hospital bed sheets.

Frequently asked questions

What are split king sheets?

Split king sheets are a bedding set designed for adjustable king bases, where the mattress is two independent twin XL halves. Ours includes two twin XL fitted sheets, a full-width king flat sheet, and two king pillowcases.

Do split king sheets fit standard king beds?

The flat sheet and pillowcases do; the fitted sheets are twin XL and won’t fit a single-piece king mattress. For a standard king, buy king bed sheets specifically.

Are split king sheets and split Cal king the same?

No — split king halves are 38 × 80 in. twin XL; split Cal king halves are 36 × 84 in. They are not interchangeable. Check your adjustable base configuration before ordering.

Do split king sheets work on flex-top mattresses?

Flex-top is a different configuration — the mattress splits only at the head end and stays joined at the foot. Our split king is fully split. For flex-top, look for that specific label.

Complete the adjustable king bed

Layer with a matching king duvet cover, coordinated king pillowcases and a light cotton quilt. For related adjustable configurations, browse the full bed sheets collection.