by A split king bed consists of two Twin XL mattresses placed side by side on a King-sized frame, creating the same overall footprint as a standard King (76" x 80"). The key difference: each Twin XL is independent, allowing couples to adjust firmness, head position, and foot position separately on each side.
Split King Dimensions
| Component | Dimensions | Notes |
|---|---|---|
| Each Twin XL mattress | 38" x 80" | Standard Twin XL size |
| Combined width | 76" (= standard King) | Same overall footprint as King |
| Length | 80" | Same as standard King |
| Frame required | King size (76x80) | Or two Twin XL adjustable bases side by side |
Why Split King? The Main Reasons Couples Choose It
1. Different Firmness Preferences
If one partner prefers a firm mattress and the other prefers soft, a split king with independently adjustable bases allows each person to dial in their own firmness level. This is the primary reason couples upgrade to split king configurations.
2. Adjustable Base Independence
The most compelling use case: one partner wants to elevate their head for snoring or acid reflux at 2am without disturbing the other. In a split king with dual adjustable bases, each partner controls their own side via a separate remote — independently raising or lowering head and foot positions.
3. Different Sleep Schedules
Split king mattresses have zero motion transfer between the two Twin XLs — there's literally a seam between them. If one partner gets up at 5am and the other sleeps until 8am, the separation eliminates motion disruption almost entirely.
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Two Twin XL AS3 mattresses + dual adjustable bases for independent head/foot control. 100-night trial, 20-year mattress warranty.
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Split King vs. King: Differences That Matter
| Feature | Split King | Standard King |
|---|---|---|
| Overall size | 76" x 80" | 76" x 80" |
| Independent firmness | Yes | No |
| Adjustable base compatible | Yes — dual independent motors | Yes, but both sides move together |
| Center seam | Yes — gap between mattresses | No |
| Motion isolation | Perfect (separate mattresses) | Depends on mattress type |
| Sheets | Specialty split king sheets needed | Standard King sheets |
| Price premium | Higher (2 mattresses + dual bases) | Standard King pricing |
Split King Sheets: What You Need
Standard King sheets don't fit a split king correctly — they'll bridge the gap but won't stay tucked when each side adjusts independently. You need split king sheets specifically designed for this configuration:
- Two separate Twin XL fitted sheets (one for each side)
- One standard King flat sheet (goes over both sides)
- Standard King pillowcases
Some couples use a "split king sheet set" which includes both fitted sheets and a King flat in a single purchase. This is the easiest solution.
Luxury Bliss hybrid available for split king setups. Each side independently adjustable, natural latex comfort.
View PlushBeds Adjustable Beds →
Frequently Asked Questions
What is a split king bed?
A split king is two Twin XL mattresses (38x80" each) placed side by side on a King frame — same 76x80" footprint as a standard King. Each side is independent for different firmness and, with dual adjustable bases, independent head/foot elevation.
Is a split king the same size as a King?
Yes. 76" x 80" — identical overall footprint. The difference is two separate Twin XL mattresses rather than one continuous surface.
What sheets do you use on a split king?
Two separate Twin XL fitted sheets + one standard King flat sheet + King pillowcases. Look for "split king sheet sets" that bundle both fitted sheets with a King flat. Standard King fitted sheets won't stay tucked during independent base adjustment.
Do you need two adjustable bases for a split king?
No, but two separate adjustable base motors are what makes a split king fully independent. A split king can sit on a standard platform frame, but the main benefit — independent head/foot elevation — requires dual adjustable bases. One King adjustable base moves both sides together.