Split King Mattress Size Guide
A Split King uses two Twin XL mattresses side by side in a King frame — ideal for adjustable base users and couples with different firmness or temperature preferences.
About the Split King Size
A Split King uses two Twin XL mattresses, each 38 × 80 inches, side by side for a 76 × 80-inch King footprint. If both partners want independent head and foot positions, pair the mattresses with a compatible split adjustable base; a single King base will not provide separate movement. The two sides can also have different feels when the manufacturer permits the chosen Twin XL models to be paired. Plan for two Twin XL fitted sheets or a Split King set with two fitted sheets, and confirm that the frame and base support the exact mattress pair. The center seam is a trade-off: a bridge may make it less noticeable on a flat bed, but check whether it interferes with independent adjustment before buying one.
Compare split-king mattresses, bases, and sheet setups →Best For
- ✓Couples who want independent head and foot positions with a compatible split base
- ✓Partners choosing different mattress feels in compatible Twin XL models
- ✓Shoppers willing to use separate fitted sheets and manage a center seam
Not Ideal For
- ✗Couples who want a seamless sleep surface
- ✗Budget buyers (two mattresses + adjustable base is expensive)
- ✗Those without the need for independent adjustment
Top Mattresses Available in Split King
Best for: Value focused shoppers who want a conventional medium firm memory foam feel · Back and stomach sleepers who do not need an extra firm surface
Why it stands out: Certification scope is specific: CertiPUR-US covers the foam layers and OEKO-TEX STANDARD 100 covers only the knit cover; Bare Home separately states that the mattress is fiberglass-free
Keep in mind: Only one feel is offered, and Bare Home itself says lighter side sleepers may prefer something softer
Buy with confidence
100-night Good Dreams comfort trial at Bare Home
Best for: Stomach sleepers · Back sleepers
Why it stands out: The simple 2-inch comfort layer over an 8-inch support core creates a flatter, lower-sink choice for back and stomach sleepers
Keep in mind: Amerisleep does not recommend this Firm model for side sleepers because the surface may not cushion the shoulder and hip enough
Best for: Foam shoppers · Back sleepers
Why it stands out: Copper-infused foam
Keep in mind: Cooling pillow top is a separate 11 inch configuration
Buy with confidence
120-night Nolah comfort trial at Nolah
Latex For Less Natural Latex Mattress
Best for: Shoppers who want Medium and Firm choices in one reversible mattress · Buyers who prefer an all latex core without pocket coils
Why it stands out: The 9-inch construction publishes 6 inches of D85 firm natural latex and 2 inches of D75 medium natural latex between organic-wool barriers
Keep in mind: The current page does not publish the exact latex-layer split inside the 7-inch model, so the 9-inch 6-plus-2-inch recipe cannot be applied to it
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120-night direct-purchase mattress trial at Latex For Less
Best for: Shoppers who want a published eight inch coil core and exact Queen coil count · Couples who prioritize reinforced edges and individually wrapped coils
Why it stands out: The product page publishes the complete support stack: three inches of organic Dunlop latex over an eight-inch wrapped-coil core
Keep in mind: The product selector says Firm while the construction section calls the 85-density latex medium-firm, so the firmer option is not described consistently
Buy with confidence
120-night direct-purchase mattress trial at Latex For Less
Best for: Side sleepers · Pressure relief
Why it stands out: AirFoam comfort layer
Keep in mind: Cooling pillow top is a separate 13 inch configuration
Buy with confidence
120-night Nolah comfort trial at Nolah
Split King Size — Frequently Asked Questions
What exactly is a Split King?
A Split King is two separate Twin XL mattresses (38×80 inches each) placed side by side in a King-size bed frame. Together they fill the same space as a King (76×80 inches). Each mattress is independent, allowing different firmness, adjustable base positions, and smart bed settings per side.
Do I need special sheets for a Split King?
Each half needs its own Twin XL fitted sheet. A Split King set normally supplies two Twin XL fitted sheets plus a King flat sheet and pillowcases; two separate Twin XL sets can also work. Check the mattress depth and the set contents before ordering.
Is a Split King more expensive than a King?
It can be, especially with independent adjustable bases. Compare the exact price of two Twin XL mattresses, the compatible base or base pair, and the sheets against the one-piece King setup you would otherwise buy. The difference depends on the models and offers you choose.
Can you feel the gap in a Split King?
The two mattresses create a center seam. How noticeable it feels depends on the mattresses, their position, and the bedding. A bridge can cover the seam on a flat setup, but check compatibility before using one with independently moving bases.
What adjustable bases work with Split King?
Look for a base configuration that supports two Twin XL mattresses and independent controls if separate movement is your goal. Confirm mattress flexibility, frame fit, weight limits, and whether the listed Split King package includes both sides before ordering.