Several of the 1- and 3-star reviews on Egyptian Linens’ split king set come from buyers whose bed only splits at the head. They needed flex-top sheets, ordered split king sheets, and got two fitted sheets for a mattress that’s one piece at the foot. The names sound alike, but the sheets aren’t interchangeable. Here’s how to tell which bed you have and what each set contains.
This guide is based on the shops’ published sizes and buyer reviews, not on sheets I’ve slept on.
In this article
The short answer
- Split king: two separate mattresses side by side. You need two twin XL fitted sheets and one king flat sheet.
- Flex-top king (also called split-top or split-head king): one mattress split only at the head. You need one fitted sheet with a split at the top.
- Check before you order: look at the foot of the bed. Two pieces means split king; one piece means flex-top.
- Where to buy: Egyptian Linens sells both, plus the California king versions. Our Egyptian Linens review covers its sizes, complaints and returns.
What is a split king?
A split king is two separate mattresses lying side by side, usually on an adjustable base, so each side can be raised on its own. One person can sit up to read while the other lies flat.
The sizes add up neatly. A standard king mattress is 76 x 80 inches, and a twin XL is 38 x 80 inches, so two twin XLs side by side make a king. A California king is 72 x 84 inches, and a split California king is two 36 x 84 inch mattresses. Our bed sizes guide has every standard US size.
Split king vs flex-top king: which bed do you have?
A flex-top king looks like a split king from the head of the bed, but it’s one king mattress that is split only at the head end. Each side’s head section can rise on its own, while the foot end stays joined. Egyptian Linens says these mattresses are sold by brands such as Sleep Number.
That’s why the sheets don’t swap. A split king set gives you two separate fitted sheets, and on a flex-top mattress the foot is one piece, so there’s nothing for two sheets to wrap around. A flex-top fitted sheet is one piece at the foot, so it can’t go on two separate mattresses.
To check your bed:
- Look at the foot of the bed with the sheets off. Two separate mattresses means split king; one piece means flex-top.
- Raise one side’s head. On a flex-top bed, the split stops partway down and the foot stays joined.
- Check the label or the manual for “split king”, “split head” or “FlexTop”.
- Measure one side’s width and the mattress depth, so you can match the pocket size.
What comes in a split king sheet set
At Egyptian Linens, a split king set has one king flat sheet (110 x 102 inches), two twin XL fitted sheets (39 x 80 inches each) and two king pillowcases (20 x 40 inches). Pockets on most of its sets are 15 to 16 inches deep. Prices run from $90 for 300 thread count to $252 for 1,000 thread count; its 600 thread count cotton set is $165, rated 4.40 stars from 92 reviews (prices checked October 2026).
The flat sheet is a single king sheet that goes over both halves. One buyer found it hard to tuck in on their bed. If you’d rather each person had their own top sheet, two twin XL sheet sets are another way to dress a split king, since each half is a twin XL size.
What comes in a flex-top king sheet set
A flex-top set has one king flat sheet, two king pillowcases, and one fitted sheet of 78 x 80 inches with a split of 30 to 32 inches from the top. That fitted sheet has six corner pockets and fabric “wings” that cover the split, so each side can move without showing the mattress underneath. Depending on the set, the pockets fit mattresses 15 to 18 inches deep.
Egyptian Linens’ flex-top sets cost $110 to $270; the 600 thread count set is $170, rated 4.55 stars from 103 reviews (checked October 2026).
California king versions
Standard king sheets won’t fit a California king: it’s 4 inches longer and 4 inches narrower. The split and flex-top versions follow the same logic:
- Split California king: two 36 x 84 inch fitted sheets (16-inch pockets on the cotton sateen set). Egyptian Linens’ sets cost $110 to $169.99.
- Flex-top California king: one 72 x 84 inch fitted sheet with a 32-inch split at the top. Sets cost $120 to $210.
Split king sheets compared
| Bed | The mattress | Fitted sheets | Search for |
|---|---|---|---|
| Split king | Two 38 x 80 in (twin XL) mattresses | Two twin XL fitted sheets | “split king sheets” |
| Flex-top king | One 76 x 80 in mattress, split at the head | One 78 x 80 in fitted sheet, split 30-32 in from the top | “flex-top” or “split-top king sheets” |
| Split California king | Two 36 x 84 in mattresses | Two 36 x 84 in fitted sheets | “split California king sheets” |
| Flex-top California king | One 72 x 84 in mattress, split at the head | One 72 x 84 in fitted sheet, split 32 in from the top | “flex-top California king sheets” |
Where to buy: Egyptian Linens
Egyptian Linens, a family business in California, sells all four types above, in cotton percale and sateen, bamboo viscose, eucalyptus TENCEL™ lyocell and flannel. Our full Egyptian Linens review covers its fabrics, what buyers like and dislike, and the return rules.
- It suits: anyone with an adjustable split king, flex-top king or either California king version, especially with a mattress 15 to 18 inches deep.
- Know before you buy: the most common complaint across the shop is wrinkles after washing, and some fitted sheets run a little large on a standard mattress.
- Returns: within 60 days of shipping if unwashed, with free US shipping on orders over $50. So put the fitted sheets on before you wash them.
If you sleep hot, the fabric matters as much as the size: our guide to cotton, bamboo and Tencel sheets explains which keeps you cooler.
Frequently asked questions
Can you use regular king sheets on a split king?
The king flat sheet works, but a regular king fitted sheet is one piece, so it can’t fit two mattresses that move separately. Use two twin XL fitted sheets instead.
Do split king sheets fit a flex-top bed?
No. A flex-top mattress is one piece at the foot, so it needs one fitted sheet that is split only at the top.
What size is each side of a split king?
Each side is a twin XL, 38 x 80 inches, so the two together make a 76 x 80 inch king. Egyptian Linens cuts its split king fitted sheets at 39 x 80 inches.
Can you use two twin XL sheet sets on a split king?
Yes. Each half is a twin XL size, so two twin XL sets fit, and each person gets their own flat sheet.
Do you need a special flat sheet?
No. Split king and flex-top sets come with an ordinary king flat sheet (110 x 102 inches at Egyptian Linens). Only the fitted sheet is special.
My verdict
Check the foot of your bed before you buy anything. Two mattresses means split king sheets: two twin XL fitted sheets and a king flat sheet. One mattress split at the head means flex-top sheets: one fitted sheet with a split at the top. Get that right, check the pocket depth, and keep the sheets unwashed until you know they fit.
Ready to order sheets for your adjustable bed?
Our review covers Egyptian Linens' split king and flex-top sets, sizes, complaints and returns.
Read our Egyptian Linens review →Sources
- Egyptian Linens: split king, flex-top king, split California king and flex-top California king product pages (sizes, prices and Judge.me ratings), checked 22 October 2026
- Egyptian Linens refund and shipping policies, checked 21 October 2026
- Standard US mattress sizes: our bed sizes guide
