Quick answer: Specialty size beds need bedding and mattresses that match their exact dimensions, and most standard sheets will not fit. Twin XL and California King bedding is easy to find. Split King uses two Twin XL fitted sheets. Olympic Queen, Full XL, Three Quarter and RV sizes need specialty sheets. Alaskan, Texas, Wyoming, Florida and Alberta Kings need specialty or made-to-measure sheets and a custom mattress. The rule is simple: buy the mattress first, measure it, then order the frame and the bedding to that measurement.
Key takeaways
- Fitted sheets must match the mattress closely. Flat sheets and duvets have more flexibility.
- For oversized kings, the frame and fitted sheets are what need to be custom. A duvet only has to be big enough.
- Always measure the actual mattress (width, length and depth) before ordering sheets or a frame. Specialty mattresses can vary by an inch or more.
- Buy at least two sets of specialty sheets. You can't run to a store for a replacement.
Specialty bed size bedding chart
| Bed size | Mattress (W × L) | Fitted sheet | Duvet / top layer | Size guide |
|---|---|---|---|---|
| Twin XL | 38" × 80" | Twin XL (widely sold) | Twin or Twin XL | Twin XL guide |
| Full XL | 54" × 80" | Full XL (specialty) | Full/Queen | Full XL guide |
| Three Quarter | 48" × 75" | Three Quarter (specialty) | Full | Three Quarter guide |
| Olympic Queen | 66" × 80" | Olympic Queen (specialty) | Queen or King | Olympic Queen guide |
| RV Short Queen | 60" × 74"–75" | RV Short Queen | Queen | RV sizes guide |
| RV King | 72" × 75"–80" | RV King | King | RV sizes guide |
| Split King | 2 × 38" × 80" | 2 × Twin XL | King | Split King guide |
| Split California King | 2 × 36" × 84" | 2 × Split Cal King halves (specialty) | California King | Split Cal King guide |
| California King | 72" × 84" | California King (widely sold) | California King or King | California King guide |
| Wyoming King | 84" × 84" | Wyoming King (specialty/custom) | Oversized King | Wyoming King guide |
| Texas King | 80" × 98" | Texas King (specialty/custom) | Custom or oversized | Texas King guide |
| Alberta King | 96" × 96" | Custom | Custom or oversized | Alberta King beds |
| Florida King | 108" × 80" | Custom | Custom | Oversized kings compared |
| Alaskan King | 108" × 108" | Alaskan King (specialty/custom) | Alaskan King or custom | Alaskan King guide |
"Specialty" means a few bedding brands make the size. "Custom" means you will usually order made-to-measure.
Can you use standard sheets on a specialty size bed?
Sometimes, for the top layers, but rarely for the fitted sheet. A fitted sheet that is too small will not stay on, and one that is too big bunches and wrinkles. Here are the workarounds that do work:
- Split King: use two standard Twin XL fitted sheets, then a King flat sheet and duvet across both mattresses.
- Wyoming King: an oversized King duvet or coverlet, at least about 100" wide, usually covers the top with some overhang.
- Olympic Queen: a King duvet works well on top. The fitted sheet still needs to be Olympic Queen size.
- Full XL and Twin XL: a Queen or Full duvet gives a generous overhang.
How to measure for specialty sheets
- Width: measure side to side across the top of the mattress.
- Length: measure from head to foot.
- Depth: measure from the bottom seam to the top, including any topper. Choose a fitted sheet pocket a little deeper than this.
- Write down all three numbers and give them to your bedding maker. Don't just give a size name, because specialty sizes vary between brands.
Where do you buy a specialty size mattress?
Most mainstream mattress stores sell only the six standard sizes. Specialty and oversized mattresses (Alaskan, Texas, Wyoming, Olympic Queen, Full XL, RV and others) come from custom mattress manufacturers and specialty sleep brands, and many build to order. Before you buy, ask about:
- The exact finished dimensions and depth
- Whether very large sizes come in one piece or in sections, which affects delivery up stairs
- The foundation it needs. Most work on a solid or closely slatted platform.
- The trial, return and warranty terms for a made-to-order size
Order of operations: mattress, frame, then bedding
- Choose the mattress and confirm its exact dimensions.
- Order the bed frame built to that measurement. A custom frame should be built around your mattress, not a nominal size.
- Order the bedding using the same measurements and the mattress depth.
- Plan delivery access for the mattress and the frame, including doorways, stairs and elevators.
How Candace & Basil helps with specialty sizes
We build bed frames in-house from solid maple hardwood, from Twin to Alaskan King, and to your exact measurements if your size is not listed. Because the frame is made after you order, we build it around the mattress you will actually use. We can also point you to trusted suppliers for specialty mattresses and made-to-measure bedding. That way you are not left to piece the whole bed together on your own.
Shop by size: Alaskan King · Texas King · Florida King · Alberta King · California King · Twin XL · All custom beds
Frequently asked questions
Do King sheets fit an Alaskan King bed?
No. A King fitted sheet is made for 76" × 80" and an Alaskan King is 108" × 108", so you need Alaskan King or made-to-measure sheets.
What sheets do you use on a Split King?
Two Twin XL fitted sheets, one on each mattress, with a standard King flat sheet and duvet on top.
Can I use Queen sheets on an Olympic Queen?
No. An Olympic Queen is 66" wide, 6 inches wider than a Queen, so Queen fitted sheets are too narrow. Use Olympic Queen fitted sheets. A King duvet works well on top.
Where can I buy an Alaskan King or Texas King mattress?
From custom mattress manufacturers and specialty sleep brands rather than standard mattress stores. Confirm the exact dimensions before ordering a frame.
Should I buy the bed frame or the mattress first?
The mattress. Measure it, then have the frame built to that measurement, especially for specialty and oversized sizes.
Related reading: Specialty size beds: every non-standard size explained · Oversized king beds compared · Made to order bed frames
Questions about a specialty size? Request a custom quote or call 1-800-961-1789.
