A split king is 2 pieces 38" x 80" and a split Cal king is also two pieces 36" x 84" — better for taller individuals.
Choosing the right mattress size is one of the most important decisions when upgrading your bedroom, especially if you're considering an adjustable bed. Two popular options for couples who want personalized comfort are the split king mattress and the split California king mattress. For a full overview of all mattress sizes, see our complete mattress size guide.
What Is a Split King Mattress?
A split king mattress consists of two Twin XL mattresses placed side by side to create a standard king-size sleeping surface. Each side can be adjusted independently when paired with an adjustable bed base, allowing each sleeper to raise or lower their head and foot positions separately. See our complete split king guide for sheets, problems, and benefits.
Split King Mattress Dimensions:
- Total size: 76 inches wide x 80 inches long
- Each mattress: 38 inches wide x 80 inches long (Twin XL)
Split king setups are also easier to move since the mattress is divided into two smaller pieces. For couples who want independent head adjustment without a full split, see our split top vs split head guide.
What Is a Split California King Mattress?
A split California king mattress works similarly but uses two long, narrow mattresses placed side by side, creating the dimensions of a California king bed while still allowing independent adjustability.
Split California King Dimensions:
- Total size: 72 inches wide x 84 inches long
- Each mattress: 36 inches wide x 84 inches long
Compared to a split king, the split California king is narrower but longer — a great option for taller sleepers who need extra legroom.
Key Differences Between Split King and Split California King
| Feature | Split King Mattress | Split California King Mattress |
|---|---|---|
| Total Width | 76 inches | 72 inches |
| Total Length | 80 inches | 84 inches |
| Individual Mattress Size | 38" x 80" | 36" x 84" |
| Best For | Couples who want more width | Taller sleepers needing more length |
In simple terms: Split King = wider, Split California King = longer. Most people choose a split king because it offers more sleeping space from side to side. However, if you or your partner are over six feet tall, the extra length of a split California king may provide better comfort.
Why Split Mattresses Work So Well With Adjustable Beds
Split mattresses are designed to pair perfectly with adjustable bed bases. Since each mattress moves independently, couples can customize their sleeping position without affecting their partner. Adjustable bases allow users to elevate their head or feet to improve circulation, reduce snoring, or simply relax more comfortably. See our zero gravity guide and best positions for back pain for more on therapeutic positioning. For a full feature breakdown, see our adjustable bed buying guide.
Mattress Types Available for Split King and Split California King
Both split king and split California king mattresses are available in several different mattress materials. See our full mattress type comparison for a detailed breakdown.
Memory foam mattresses contour closely to the body and relieve pressure points — read more about the health benefits of memory foam.
Latex mattresses offer responsive support and natural breathability — read more about the health benefits of latex.
Hybrid mattresses combine foam comfort layers with pocketed coil support systems — see our hybrid vs memory foam comparison.
Some couples also prefer adjustable air mattresses, which can be custom made into split Cal king sizes allowing each sleeper to customize firmness levels independently. See our air adjustable mattress guide and split top air adjustable guide for more. Not sure on firmness? See our mattress firmness guide.
Which Split Mattress Size Is Best?
A split king mattress is the most common option because it provides more width and works well in standard king-size bed frames. A split California king mattress may be the better option if you are taller than 6'2", your bedroom is narrower but longer, or you prefer additional legroom while sleeping.
Both mattress types deliver the key advantage couples want: independent comfort on each side of the bed. We also have both split king and split Cal king configurations in complete bundle sets under $2,000 and our bundles under $2,500 guide for more options.
If you're shopping for a complete sleep system, browse our selection of Split King Adjustable Beds designed for couples who want independent comfort and positioning.
Final Thoughts
Split mattresses have become increasingly popular as adjustable bed systems continue to grow. Both split king and split California king mattresses offer couples the flexibility to sleep independently while sharing a bed. Also see our complete guide to split mattresses for a full overview of all split configurations, and our split queen guide if you need a smaller footprint.
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