King and California King sound like the same bed with a bit of West Coast branding attached. They aren't. They're different shapes, they take different sheets, and buying the wrong one is one of the more expensive bedding mistakes you can make.
The difference comes down to four inches, traded in opposite directions.
The two sizes
| King | California King | |
|---|---|---|
| Width | 76" | 72" |
| Length | 80" | 84" |
| Also called | Eastern King, Standard King | Cal King, Western King |
A King is four inches wider. A California King is four inches longer.
The total surface area is almost identical — 6,080 square inches versus 6,048 — which is why the two feel comparable in a showroom and why the distinction slips people's minds by the time they're buying sheets.
Which one suits which sleeper
A King suits most couples. Thirty-eight inches of width each is the same personal space as a twin bed, which is the real argument for a king in the first place. If you share with a partner, a child who migrates at 2am, or a dog with opinions, width is what you want.
A California King suits tall people. If you're over about six foot two, those four extra inches of length are the difference between your feet under the covers and your feet out in the cold. It also fits better in a long, narrow room — the kind of bedroom where a king would leave you edging sideways past the footboard.
There's a practical consideration too: a California King is harder to shop for. Fewer manufacturers make bedding for it, so your choice of sheets, duvet covers and mattress protectors is genuinely narrower. Worth knowing before you commit.
Sheets are not interchangeable
This is the part that costs money.
A King fitted sheet on a California King mattress will be four inches too short lengthwise. It will go on — cotton jersey has plenty of give — and then pull off the corners at the head and foot, because the fabric is being asked to span a distance it wasn't cut for.
A California King fitted sheet on a King mattress is four inches too narrow. Same outcome, different axis.
Flat sheets are more forgiving, since they're loose anyway, but you'll notice the shortfall in how much tucks in at the sides. Duvet covers are similarly fussy.
Our King sheets and California King sheets are cut separately for exactly this reason, and both are made for mattresses up to 16 inches deep.
The one thing that is shared
Pillowcases. Both use King pillowcases, roughly 20" × 40" — longer than the standard/queen size at 20" × 30". If you're buying pillowcases on their own, King is King regardless of which mattress you have.
Our pillowcases come in two-packs in both sizes.
How to tell what you've got
Measure the width. That single number settles it — 76 inches is a King, 72 inches is a California King. You don't need to measure the length at all.
If the mattress has a label, it'll say. But labels fall off, and beds get inherited, and it takes ten seconds with a tape measure.
Questions we get asked
Is a California King bigger than a King?
Not really. It's longer but narrower, and the total area is about 32 square inches smaller — a rounding error on a bed this size.
Can I use King sheets on a California King?
Not well. They're four inches short lengthwise and the corners will pull off.
Which is better for couples?
King, in most cases. Width is what you feel when you share a bed.
Which is better for tall people?
California King, if you're much over six foot two.
Do they use the same duvet cover?
Often the same nominal size, but the fit differs. Check the dimensions rather than the label.
Is a Split King the same thing?
No — that's two Twin XL mattresses side by side, usually on an adjustable base, and it takes two Twin XL fitted sheets.
Measure the width, then browse King or California King sheets — 100% Turkish cotton jersey, OEKO-TEX certified.