The California King oversized duvet measures 110 inches by 100 inches (279 cm by 254 cm). This is the correct size for California King beds and for anyone with a deep, thick, or pillow-top mattress where standard King bedding falls short on all sides. A standard King duvet, by comparison, measures only 102 inches by 90 inches (259 cm by 229 cm) — a difference of 8 inches in width and 10 inches in length.
If you've ever made your bed with a King duvet and noticed it barely reaches the sides of the mattress, you now know why. You need the California King oversized size.
Complete Bedding Size Comparison Chart (Imperial and Metric)
| Size | Width × Length (inches) | Width × Length (cm) |
|---|---|---|
| Twin / Single | 60" × 80" | 152 cm × 203 cm |
| Double / Full | 80" × 86" | 203 cm × 218 cm |
| Queen | 86" × 90" | 218 cm × 229 cm |
| King (Standard) | 102" × 90" | 259 cm × 229 cm |
| California King Oversized | 110" × 100" | 279 cm × 254 cm |
Most Canadian bedding retailers only stock standard King (102" × 90" / 259 cm × 229 cm). Down Under Bedding is one of the few Canadian sources carrying the true California King oversized size at 110" × 100" (279 cm × 254 cm) — available in both the goose down duvet and the coordinating cotton duvet cover set.
What Is the California King Oversized Size?
Customers ask us this question regularly. The California King oversized size is the next bedding size above standard King. It was designed specifically for:
- California King mattresses (72" × 84" / 183 cm × 213 cm), which are 4 inches longer than a standard King
- Thick, deep mattresses — anything 15" to 20" (38 cm to 51 cm) in depth — where standard bedding rides up and leaves the sides of the mattress exposed
- Pillow-top mattresses, luxury foam mattresses (Tempur-Pedic, Endy premium, Sleep Country top-tier lines), and adjustable bed bases that add height
- Anyone who has tried a standard King duvet on a larger bed and found it too short on the sides
The rule of thumb for proper drape is 10 to 12 inches (25 to 30 cm) of coverage on each side of the mattress. On a standard King mattress with a regular King duvet, you may get as little as 5 to 6 inches per side. On a thick or California King mattress, the standard King duvet barely reaches the edge at all. The 110" × 100" (279 cm × 254 cm) oversized California King solves this completely.
California King vs Standard King: The Key Differences
A California King mattress is 4 inches longer and 4 inches narrower than a standard King mattress. This sounds like a small difference until you're shopping for bedding and realize that most stores only stock standard King sizes.
Here is the direct comparison:
Standard King mattress: 76" × 80" (193 cm × 203 cm) California King mattress: 72" × 84" (183 cm × 213 cm)
Standard King duvet: 102" × 90" (259 cm × 229 cm) California King oversized duvet: 110" × 100" (279 cm × 254 cm)
The California King mattress is ideal for taller sleepers — anyone over 6 feet (183 cm) who wants legroom — and for people who prefer the longer, narrower profile. If you share the bed and value width for comfort, standard King gives you more lateral room. This is where you can look at the bamboo duvet covers in all the sizes on our website.:
Who Should Buy the California King Oversized Duvet?
Taller sleepers. Anyone 6 feet (183 cm) or taller sleeping on their back or stomach will feel the difference in length. The extra 10 inches (25 cm) in the California King oversized duvet compared to a standard King ensures full coverage from shoulder to foot.
Pillow-top and luxury mattress owners. High-end mattresses commonly run 15" to 20" (38 cm to 51 cm) in depth. Every extra inch of mattress depth reduces how far your duvet hangs on the sides. If you have invested $2,000 or more in a premium mattress, the last thing you want is a $60 duvet that doesn't cover it properly.
Adjustable base owners. Adjustable bases — commonly used for sleep apnea, acid reflux, back pain, or personal comfort — add height to your sleeping surface. Owners of adjustable beds consistently report that standard bedding is the first thing they have to replace after upgrading their base.
Couples who want full coverage on both sides. Standard King duvets are shared between two people pulling in different directions. The extra 8 inches (20 cm) of width in the California King oversized means both partners have coverage without a tug-of-war. No more waking up cold because someone stole the duvet.
People replacing bedding on a recently upgraded mattress. Many customers find this page after upgrading to a thicker or larger mattress and discovering their existing bedding no longer fits. This is the correct replacement size.
The Complete California King Oversized Sleep System
Finding the right duvet is only half the solution. You also need a duvet cover that actually fits a 110" × 100" (279 cm × 254 cm) insert. Most duvet covers sold as "King" in Canada are sized for 102" × 90" (259 cm × 229 cm) — they will be too small, causing your duvet to bunch inside the cover.
Down Under Bedding carries the complete California King oversized sleep system:
The Duvet: Cal King Goose Down Duvet — 110" × 100" (279 cm × 254 cm). Filled and finished in Canada with 550 loft white goose down. 289 thread count 100% cotton down-proof cover. Secure corner tie grips. Hypoallergenic and dust mite resistant. Baffle box construction prevents fill from shifting.
The Cover (Cotton): California Super King Cotton Duvet Cover Set — 110" × 100" (279 cm × 254 cm). 400 thread count 100% cotton. Includes 2 King pillow shams (38" × 21" / 97 cm × 53 cm). Zipper closure. Corner ties inside to anchor your duvet. Machine washable.
The Cover (Bamboo): Cal King Bamboo Duvet Cover — 110" × 100" (279 cm × 254 cm). 310 thread count 100% bamboo. Ultra-soft, hypoallergenic, temperature regulating. Available in spa blue and white.
Buying the duvet and the matching cover together is the correct approach — both sized at 110" × 100" (279 cm × 254 cm), so the insert fills the cover properly and the system looks and performs as intended.
What Customers Say
"Finally found a duvet cover that actually fits my Cal King bed properly! The 110×100 dimensions are spot on. The cotton is high quality — feels smooth and substantial, not cheap or thin. I love that it came with the corner ties to keep the duvet from shifting around." — Verified buyer, Down Under Bedding
"I have been looking forever for a duvet and duvet cover that actually fits my bed and this is perfect!" — Verified buyer, Down Under Bedding
Frequently Asked Questions:
Where can I buy the 100% cotton California King size duvet covers?
What size is a California King duvet? A California King oversized duvet measures 110 inches by 100 inches (279 cm by 254 cm). This is the correct size for California King mattresses and for thick, deep-pocket mattresses where a standard King duvet (102" × 90" / 259 cm × 229 cm) falls short.
What is the difference between a King and a California King duvet? A standard King duvet measures 102" × 90" (259 cm × 229 cm). A California King oversized duvet measures 110" × 100" (279 cm × 254 cm). The California King is 8 inches wider and 10 inches longer. If you have a California King mattress or a thick luxury mattress, you need the California King oversized size for proper coverage.
Is the California King bigger than a regular King? The California King mattress is actually 4 inches narrower than a standard King mattress, but 4 inches longer. The California King oversized duvet, however, is larger than a standard King duvet in both width and length — 110" × 100" (279 cm × 254 cm) versus 102" × 90" (259 cm × 229 cm) — because it is designed to drape properly over the full surface of a larger or deeper mattress.
Why doesn't my King-size duvet fit my California King bed? A standard King duvet is only 102" × 90" (259 cm × 229 cm). A California King mattress is 72" × 84" (183 cm × 213 cm), which means after accounting for mattress depth, a standard King duvet barely reaches the edges. You need the 110" × 100" (279 cm × 254 cm) California King oversized duvet for full drape on all sides.
Where can I buy a California King oversized duvet in Canada? Down Under Bedding is one of the few Canadian retailers carrying the true California King oversized duvet at 110" × 100" (279 cm × 254 cm), filled and finished in Canada with white goose down. The coordinating cotton duvet cover set and bamboo duvet cover in the same size are also available. Ships free across Canada.
What size duvet cover fits a 110" × 100" duvet? You need a duvet cover specifically sized for California King oversized / Super King at 110" × 100" (279 cm × 254 cm). Standard King duvet covers (102" × 90" / 259 cm × 229 cm) are too small — your duvet will bunch inside the cover. Down Under Bedding carries both a cotton and a bamboo duvet cover in the correct 110" × 100" (279 cm × 254 cm) size.
What is the difference between California King and Super King? In Canada and the United States, California King oversized and Super King both refer to the 110" × 100" (279 cm × 254 cm) duvet size. In the United Kingdom, Super King refers to a different mattress size (72" × 78" / 183 cm × 198 cm) that is actually smaller than a North American standard King. If you are shopping in Canada, California King oversized and Super King mean the same thing.
Is a California King mattress the same as a Super King mattress? Not in Canada. In Canada, California King is 72" × 84" (183 cm × 213 cm). In the UK, Super King is 72" × 78" (183 cm × 198 cm). They are different sizes. Canadian buyers should shop for California King bedding, not UK Super King sizing.
Down Under Bedding has supplied premium natural bedding to Canadian customers for nearly 40 years. Free shipping across Canada. Contact us by text, chat, or email.
Leave a comment (all fields required)