A split king adjustable bed usually has two separate 39-by-80-inch mattresses, so the right cover needs to fit each side without bunching as the bed moves. But “split king” can also mean a single mattress with a split near the head, so check the shape carefully before you buy. These picks include both standard split-king protectors and split-top designs, with options for a thin waterproof layer or a lightly quilted surface.
Quick Comparison
| Product | Best for | Design | Fit details |
|---|---|---|---|
| Kingnex Waterproof Split King Mattress Protector | Keeping the mattress feel unchanged | Thin bamboo-viscose blend, waterproof | Two 39-by-80-inch covers; up to 18 inches deep |
| SPRINGSPIRIT Split Top King Mattress Protector | A flex-head, split-top king | Quilted polyester surface, waterproof | 78-by-80-inch cover; 34-inch head split; up to 18 inches deep |
| KUTUU Waterproof Split King Mattress Protector | Quilted protection for two mattresses | Polyester quilted surface, waterproof | Two 39-by-80-inch covers; 6–18-inch pockets |
| SPRINGSPIRIT Split King Mattress Protector Pad | A standard two-piece split king | Quilted polyester surface, waterproof | Two 39-by-80-inch covers; check the listing for pocket depth |
| KUTUU Cooling Split Top King Mattress Protector | A split-top design with a bamboo-derived fabric blend | Lightweight, waterproof, breathable fabric | 78-by-80-inch cover; 32–34-inch head split; 6–18 inches deep |
Our Picks: Best Mattress Pad For Split King Adjustable Bed reviews
1. Kingnex: A Thin, Waterproof Cover for Standard Split King Beds
The Kingnex set includes two fitted protectors, each sized for one 39-by-80-inch split-king mattress. Its surface is made from 70% bamboo-derived viscose and 30% cotton, with a TPU waterproof membrane underneath. The fitted-sheet style has stretchable pockets designed for mattresses up to 18 inches thick.
This is a protector, not a cushioned mattress pad. It has no padding or quilting, so it is a useful choice if you want liquid protection without adding much loft or changing the feel of your mattress. The soft, moisture-wicking surface may also appeal to sleepers who prefer a less plasticky-feeling cover.
Because it comes as two separate pieces, each side can move with its own adjustable base. The trade-off is that it will not add softness or cushioning. It is also important to match the 39-by-80-inch size to two separate mattresses; it is not the one-piece cover for a split-top king.
Pros:
- Two fitted covers sized for standard split king mattresses
- Waterproof TPU backing
- Thin construction helps preserve the mattress’s original feel
- Machine washable; tumble dry on low
Cons:
- No quilted padding to add softness
- Not designed as a single split-top king cover
Verdict: Choose Kingnex if you need waterproof protection for a standard split king and want a thin cover rather than a cushioned pad.
2. SPRINGSPIRIT: A Quilted Cover for Split-Top Flex-Head Beds
This SPRINGSPIRIT cover is made for a split-top king, not a standard split king with two fully separate mattresses. It measures 78 by 80 inches and has a split about 34 inches from the head, allowing the top sections of a flex-head bed to move independently while the lower portion remains joined.
The quilted polyester face and filling provide more softness than a thin protector, while a polyurethane backing provides waterproof protection. Its long skirt is listed to fit mattresses up to 18 inches deep. The product information also describes the surface as absorbent and breathable, though the added quilting means it will feel different from a bare mattress.
The key buying decision is the bed layout. This one-piece cover is aimed at a mattress that splits at the head, so it is not the right shape for two separate 39-by-80-inch mattresses. Its product details emphasize the 34-inch head split, making it especially important to compare that measurement with your mattress.
Pros:
- Designed for a split-top flex-head king
- Quilted surface adds a layer of softness
- Waterproof backing helps protect against spills
- Long skirt accommodates mattresses up to 18 inches deep
Cons:
- Not intended for a standard, fully split king
- Quilting may change the feel more than a thin protector does
Verdict: This is a practical option if your bed has one king-size mattress with a split at the head and you want both waterproofing and a quilted surface.
3. KUTUU: Quilted Waterproof Protection in a Two-Cover Set
KUTUU’s standard split-king protector comes as two covers, each measuring 39 by 80 inches. The polyester cover has a quilted surface and TPU backing for waterproof protection. A 360-degree elastic skirt is designed to hold each protector in place, with pockets listed for mattress depths from 6 to 18 inches.
The quilted construction makes this a better fit for shoppers who want a little more surface cushioning than the Kingnex offers. Box stitching is intended to help keep the filling evenly distributed, and the care instructions call for machine washing and low-heat tumble drying. The product advises against ironing, dry cleaning, and bleaching.
As with any quilted protector, expect a more noticeable layer between you and the mattress than with a thin cover. The available product details describe the surface as breathable and noiseless, but fabric feel can be personal. This set is for two separate mattresses, not a single split-top king mattress.
Pros:
- Two covers fit a standard split-king setup
- Waterproof TPU backing
- Quilted surface offers more padding than a thin protector
- Wide stated pocket range of 6 to 18 inches
Cons:
- Polyester quilting may feel warmer or thicker than a thin cover
- Not made for a one-piece split-top king mattress
Verdict: Consider this KUTUU set if you have two separate adjustable-bed mattresses and want quilted waterproof coverage with a broad pocket-depth range.
4. SPRINGSPIRIT: A Quilted Two-Piece Set for Standard Split Kings
This SPRINGSPIRIT option is a two-piece set for a standard split king. Each cover measures 39 by 80 inches, with a quilted polyester face, a polyurethane waterproof layer, and a polyester skirt. Unlike the brand’s split-top option, these covers are separate and are meant to fit the two mattresses individually.
The quilted surface adds a softer layer while the waterproof backing helps guard against spills and stains. The listing describes the set as machine washable and notes that the products are vacuum packed for shipping, so they may arrive looking flat or creased. Following the care instructions is the suggested way to help them regain their loft.
The supplied product details are inconsistent about the pocket depth: the description mentions a fit up to 18 inches, while a product highlight refers to a deep pocket up to 14 inches. Check the current listing and your mattress measurements before ordering, especially if your mattresses are unusually deep. This is also a more padded choice than Kingnex, so it may alter the mattress feel more.
Pros:
- Two covers sized for separate 39-by-80-inch mattresses
- Quilted surface adds some cushioning
- Waterproof layer helps protect against liquids
- Machine washable
Cons:
- Product information gives conflicting pocket-depth details
- Not suitable for a split-top king mattress
Verdict: This set may suit a standard split king if you want quilted coverage, but verify the pocket depth in the listing before buying.
5. KUTUU Cooling: A Split-Top Cover with a Bamboo-Derived Blend
This KUTUU cover is built for a split-top king mattress. It measures 78 by 80 inches and has a 32-to-34-inch split near the head. The fabric is listed as 60% polyester and 40% viscose derived from bamboo, with waterproof TPU backing. The deep pocket is designed for mattresses from 6 to 18 inches thick.
Its lightweight construction is meant to provide waterproof protection without the feel of a thick quilted pad. The product describes the fabric as breathable and moisture-wicking, and it is machine washable. This may appeal if you want a smoother cover and prefer bamboo-derived viscose, while still needing a split-top design.
Measure the split from the head of your mattress before ordering. This is one full-size cover with a partial split, not a two-piece set for a standard split king. Although the product is described as cooling, that term does not guarantee a particular sleep temperature; your bedding, room, and personal comfort all matter.
Pros:
- Designed specifically for a split-top king
- Waterproof backing with a lightweight surface
- Bamboo-derived viscose blended with polyester
- Deep pocket fits mattresses listed from 6 to 18 inches
Cons:
- Not a two-piece protector for a standard split king
- Head-split placement must match your mattress
Verdict: Pick this KUTUU cover if you have a split-top king and want a lightweight waterproof protector with a bamboo-derived fabric blend.
How to Choose a Mattress Pad for a Split King Adjustable Bed
Confirm whether your bed is a standard split king or split-top king
A standard split king usually has two separate mattresses, each about 39 by 80 inches. It generally needs two individual fitted covers. A split-top king uses one king-size mattress with a split near the head, so it needs a one-piece cover with a matching split. These designs are not interchangeable. Check your mattress and the product’s size diagram before you order.
Measure the mattress depth and split location
Measure the mattress thickness from the bottom edge to the top surface, including any attached pillow top. Compare that measurement with the cover’s stated pocket range. For a split-top mattress, also measure how far the split extends from the head. The products here list different split positions, and even a small mismatch can affect how the cover fits when the bed is raised.
Decide between a thin protector and a padded pad
A thin protector is a good match if you want to preserve the mattress’s existing feel while adding a barrier against liquids. A quilted cover adds some softness but creates a more noticeable layer. If your main goal is a comfort upgrade, check how much filling the pad has; these product details describe quilted surfaces but do not give a specific thickness for the padding.
Choose the protection and fabric that suit your needs
All five picks describe a waterproof layer, but their top fabrics differ. Kingnex uses a bamboo-viscose and cotton blend, while several other options use polyester. The KUTUU split-top cover lists a polyester and bamboo-derived viscose blend. Consider the feel you prefer, and follow the care instructions to help maintain the cover and its waterproof layer.
Consider how each mattress moves
For a standard split king, two separate fitted covers can move with each mattress independently. For a split-top king, a one-piece cover needs a head split that lines up with the bed’s moving section. The right shape helps reduce pulling and bunching as you adjust the bed. Secure elastic skirts and a suitable pocket depth also help keep a cover in place.
Check care instructions and listing details
Machine-washable covers are convenient, but the allowed drying temperature and other care limits vary. Review the product listing for the latest sizing and instructions, particularly when product details give more than one pocket-depth measurement. Use the actual mattress dimensions rather than relying only on a general “king” label.
Frequently Asked Questions
Is a split king the same as a split-top king?
No. A standard split king has two separate mattresses. A split-top king generally has one king-size mattress with a split near the head. Each setup requires a different style of cover, so confirm your mattress layout before buying.
Can I use a regular king mattress pad on a split king adjustable bed?
A regular one-piece king pad may not fit two separate mattresses properly or move with them independently. For a standard split king, look for a two-piece set sized for the individual mattresses. For a split-top king, choose a cover with the right head split.
Will a waterproof protector make my mattress feel different?
It can, depending on its fabric and construction. A thin, unquilted protector like Kingnex is designed to preserve more of the mattress’s original feel. A quilted option adds a more noticeable layer of softness.
Do these covers fit every mattress depth?
No. Pocket ranges vary, and one SPRINGSPIRIT listing includes conflicting depth information. Measure your mattress and check the product listing for the pocket range before ordering.
Is a mattress protector the same as a mattress pad?
Not always. A protector mainly shields the mattress, often with a waterproof barrier. A pad usually adds some cushioning, though product names can use the terms loosely. Check the construction details to see whether the cover is thin or quilted.
Can I wash these mattress covers?
The supplied details describe all five as machine washable, but care instructions differ. Follow the instructions for the specific product, including any limits on water temperature, drying, bleach, or ironing.
Which option is best if I am unsure what kind of split my bed has?
Measure the mattress layout first. If you have two separate mattress pieces, look at the standard split-king options. If you have one mattress with a split near the head, compare the split location with the two split-top covers here. Choosing by the word “king” alone can lead to the wrong fit.
Final Recommendation
For a standard split king, the Kingnex set is a straightforward choice if you want waterproof protection without added quilting. If you prefer a padded surface, compare the quilted KUTUU and SPRINGSPIRIT two-piece options and verify the pocket depth. For a split-top king, choose a one-piece cover that matches your mattress’s head-split measurement: SPRINGSPIRIT offers a quilted surface, while KUTUU provides a lighter bamboo-derived fabric blend. The most important step is matching the cover style to your bed’s exact layout.
