To split or not to split, that is the question. The term "split king-sized bed" means a bed set sold in halves that fit together to make a king bed. Split king may refer to the mattress, the foundation, or both; in any case, it makes the bed far more manageable when it comes to fitting it through doorways and around corners.
Split for Convenience
A split king-sized mattress is actually two mattresses paired together. Two twin XL mattresses equal one split king. Together, the split king measures 76 inches wide, 80 inches long, or the same as a regular king-sized mattress. Moving two smaller mattresses is a bit easier for most people than moving one large, unwieldy king mattress, especially when dealing with stairs or narrow hallways or turns. If the bed is not an adjustable variety, a king-sized sheet set can be used to cover both mattresses at once, giving the appearance of a regular king-sized mattress. Twin XL sheets can also be used.
Some retailers also carry half-split king sheets, specially shaped to accommodate adjustable beds. The bottom half of each fitted sheet looks like a standard king sheet, while the top portion looks like two twin sheets. This way, an adjustable bed can move up and down on either side without the sheet popping off.
What About That Base?
Some split-king mattresses are sold with a base or foundation that is also two separate units, again for convenience. Since a bed foundation isn't usually flexible, it can be difficult to navigate even a full-sized variety through hallways or stairwells. Two narrow bases instead of a gigantic king base means much less hassle when it comes to moving the bed to its proper location. If you're purchasing a complete bed set sold as a "split king-sized bed," the mattress, as well as the base, each likely contain two paired pieces. The mattresses and bases can also be purchased separately. If you already have a standard, non-adjustable king-sized foundation, it can be used with split mattresses. A typical king mattress can also be placed atop a split foundation of the non-adjustable variety.
Another advantage of purchasing a split-king bed base is that some are adjustable, allowing you to raise your side of the bed to read a book, for instance, while your partner sleeps in fully reclined position. Some also allow both the head and foot areas to be raised or lowered. Only those sold as adjustable foundations actually contain the motors needed to move the base up and down with a controller. Any split-king mattress set can be used with a split-king adjustable base, as the mattresses do not contain motors or electronics of any sort.
Divided King: Different Base Setup
Numerous available bed options can make it hard to decide which type is best for you. In some cases, the names can be confusing as well, such as terms like split king and divided king, which sound like terms for the same thing but are actually different.
A divided-king bed refers to the base or foundation, rather than the mattress. This foundation has two separate parts that align sideways, with one piece at the head and one at the foot. If you want an adjustable bed that raises the entire head area up at the same time and at the same angle, a divided-king base is what you need.
Adjustable split-king beds, on the other hand, allow the person on each side of the bed to raise or lower the head to their liking, thanks to separate motor assemblies in each piece of the foundation. Compared to a divided king, the split-king setup typically costs a little more since it has two separate motor systems inside. An adjustable split-king foundation usually aligns side by side, just like the split-king mattress, to accommodate both motor setups. Some specialty manufacturers offer their own variations of split or divided king beds.
Kathy Adams is an award-winning writer. She is an avid DIYer that is equally at home repurposing random objects into new, useful creations as she is at supporting community gardening efforts and writing about healthy alternatives to household chemicals. She's written numerous DIY articles for paint and decor companies, as well as for Black + Decker, Hunker, SFGate, Landlordology and others.