A standard king mattress is 76 inches wide and 80 inches long (6 feet 4 inches by 6 feet 8 inches), about 193 by 203 centimetres. A California king is 72 by 84, four inches narrower and four inches longer. A split king is two twin XL mattresses side by side, 38 by 80 each, which add up to the same 76 by 80. In Canada a king means the standard 76 by 80, the size Americans call an eastern king.
At Merit Home Furniture on Vancouver Island, 10 of the 14 mattresses listed for our Duncan store come in a king, 6 from Restonic and 4 from Restwell. None of them lists a California king on its page, so a California king mattress is a question to ask the store. Before anyone picks a king mattress by feel, I want two numbers: the width of the bedroom wall and the width of the narrowest turn on the stairs.
King size mattress dimensions next to the queen and full
| Size | Inches | Cm | Each |
|---|---|---|---|
| King | 76 x 80 | 193 x 203 | 38 in |
| California king | 72 x 84 | 183 x 213 | 36 in |
| Split king, each half | 38 x 80 | 97 x 203 | 38 in |
| Queen | 60 x 80 | 152 x 203 | 30 in |
| Full or double | 53 x 75 | 135 x 191 | about 27 in |
The king and the California king cover almost the same sleeping area, 6,080 square inches against 6,048. What changes is the shape. A king adds 16 inches of width over a queen and no length at all, and that width is what a couple gains.
The full, which Canadians usually call a double, is 53 x 75 on the Better Sleep Council's chart, and some makers print 54 x 75. The council puts each of two sleepers on a full at about 27 inches, the width of a crib.
Labels round in general, and the Each column assumes two sleepers. Sealy Canada lists its king at 76 x 79.5, and the industry dimension table Serta publishes lets a finished mattress run half an inch either way. A queen has its own feet and centimetres breakdown, and every size from crib to king sits on one Canadian size chart.
Are there two sizes of king size beds?
King beds come in two mattress sizes, the standard king and the California king, and each can be split in half. The standard king is the wide one: two adults each get 38 inches, the width of a twin XL.
The California king is the long one. The Better Sleep Council calls it popular on the West Coast, and the four extra inches help someone whose feet already reach the end of an 80 inch bed. Each of two sleepers gets 36 inches. For a couple of average height, losing four inches of width is usually the bigger trade.
A Canadian king size bed is the same 76 by 80 standard king. There is no separate Canadian measurement. Sealy Canada's king label matches the American standard to within half an inch.
Uncommon king sizes: split king, split California king, RV and oversize
A split king is two twin XL mattresses on one frame. Couples choose it so each side can take a different feel, or so each person can raise their own half on an adjustable base. With two mattresses, it is one answer to a partner's motion crossing the bed.
A split California king works the same way with two long, narrow halves. The industry table lists the California king foundation as 35-1/2 x 83, two required. No mattress listing on our pages offers the split long size, so it is a special order question.
RV kings are their own sizes, and none of the beds listed for our Duncan store comes in one. A trailer king is matched to the old mattress, so its width and length are the two numbers to bring when calling us.
Alaskan, Texas and Wyoming kings are custom oversize beds, and no maker on the Merit site lists one.
King bed frame sizes: the outside measurement on our listings
A king bed frame is wider and longer than the mattress it holds. Most of the king frames Merit sells through Duncan list an outside width, and those widths run 78 to 90 inches. Four of them show the spread, outside width by length in inches, with the king price:
| Frame | King | Cal king |
|---|---|---|
| Alisdair sleigh bed, $399.00 | 78 x 85 | 78 x 94 |
| Juararo panel bed, $549.00 | 80 x 86.25 | 80 x 90.25 |
| Brintstreet upholstered bed, $799.00 | 90 x 92 | 90 x 96 |
| Aspen panel bed, $1,449.00 | 80 x 84 | Not offered |
Prices are before applicable taxes, read from our listings on October 16. Across the more than 35 king frames with a price, the range is $399 to $3,449. The top of that range is the Mako Belmont side storage bed, which measures 124 inches across because its floating nightstands are part of the frame.
The three Ashley beds above are the only Duncan frames that also come in a California king. Their California king versions run 4 to 9 inches longer than the king. Ashley frames take 4 to 6 weeks to arrive, and Mako frames 8 to 10 weeks. More frames in every size are under beds.
What size room does a king bed need?
A king bed needs a room about 10 feet 8 inches wide and 9 feet long for a tight fit. That figure takes the Aspen frame at 80 x 84 inches and adds a 24 inch walkway on both sides and at the foot. The result is 128 by 108 inches, before nightstands.
A California king frame like the Alisdair, 94 inches long, pushes the room's length to 118 inches, close to 10 feet.
For an accessible bedroom, the CMHC's universal design table asks for 1,800 mm on one side and at the foot, and 1,200 mm on the other side. With the same 80 x 84 frame, that comes to a room of 16 ft 6 in by 12 ft 11 in. Anyone planning a bedroom around a mobility aid should check the clearances with their occupational therapist.
King foundations, adjustable bases and getting a king upstairs
A king foundation comes in two halves even when the mattress is one piece. Sealy Canada says its king-size foundations come in two pieces "for easier access through narrow halls." The industry table Serta publishes sizes each king foundation half at 37-1/2 x 79, two required.
Neither Restwell nor Restonic lists a king box spring or platform base for our Duncan store. The Restwell Peak adjustable base is listed there in twin XL at $999.00 before applicable taxes, and two of them sit side by side under a split king.
The mattress is the harder part. A one-piece king is 76 inches wide. Sealy Canada says not to bend its mattresses beyond 25 degrees, to protect the innerspring, so a coil king will not fold around a landing. The headboard is the other wide rigid piece, since a frame like the Juararo measures 80 inches across. A split king goes up as two 38 inch halves, which is the usual way around a tight turn.
Adjustable bases follow the same split. Tempur-Pedic's Reflexion Arc base is listed at 78 x 80 x 16 inches in king and 39 x 80 in twin XL. That means a shared or adjustable base can be one king piece or two twin XL bases under a split king.
The Reflexion Arc is carried at our Campbell River store, which gives our best price on it by phone. Merit lists every base under adjustable bases, and the Restwell ones listed for Duncan show their price.
What a king mattress costs over a queen on our listings
A king mattress usually costs a few hundred dollars more than the same model in a queen. All 10 Duncan mattresses that come in a king price it above the queen, from $250.00 more on the Robin to $800.00 more on the Restwell Copper Hybrid. The Restwell Savannah Plush is close behind at $750.00 more. Three of them show the spread:
| Mattress | King | Over queen |
|---|---|---|
| Restwell Robin (queen $1,049.00) | $1,299.00 | $250.00 |
| Restonic Minto (queen $1,199.00) | $1,649.00 | $450.00 |
| Restonic Treviso (queen $2,599.00) | $3,299.00 | $700.00 |
Those three prices are before applicable taxes, read October 16. Kings from Tempur-Pedic, Beautyrest and the other makers belong to our Campbell River and Port Alberni stores. The Tempur LuxeAlign king is carried at Campbell River, and a call there gets our best price on that king. Mattresses arrive in 2 to 3 weeks, ready for pickup or delivery.
Bedding steps up with the bed. The Health Guard Bamboo Plus protector is $79.00 in a king and $89.00 in a California king before applicable taxes, and California king sheets are a separate size from king sheets.
When a king is the wrong size, and when California king is
- A bedroom under about 10 feet 8 inches across. A queen frame gives back 16 inches of wall for the walkway.
- A California king for a couple of average height. It trades four inches of width for length neither person uses, and only three Duncan frames come in that size.
- A one-piece coil king for a house with a tight landing. A split king is the safer order, and a photo of the turn with a tape measure in it settles the question.
- An old king foundation under a new mattress. Makers size the foundation to the mattress, so a new king usually goes on its own two halves.
Where these king measurements come from
- Better Sleep Council, mattress size chart (king, California king and full), read on 2 October 2026.
- Sealy Canada, FAQs (mattress dimensions and two-piece king foundations), read on 2 October 2026.
- Serta, Size and Dimensions (ISPA dimension standard table), read on 2 October 2026.
- CMHC, Universal Design minimum eligibility requirements table, item 61, read on 2 October 2026.
- Merit Home Furniture product listings for mattresses, bed frames, adjustable bases and bedding, dimensions read October 2, 2026, prices and listings read again October 16, 2026, and the Duncan delivery and pickup terms.
Trying a king mattress on the Island
Once you've decided a king is the right size, the feel is the next choice. Lying on a king and a queen side by side shows the width difference fast. A call ahead tells you which beds are set up at the Merit showroom you plan to visit. Our Duncan store is open Monday to Saturday, 9 to 5.
The Duncan store charges $150 across the Island, assembly included, for a king bed, and Gulf Island runs reach some islands, with the details on a call. A king mattress travelling up or down the Island can need another shipping method, which we sort out at the order. Picking up at Duncan costs nothing. Nanaimo, Campbell River and Port Alberni quote their own delivery.
The king mattresses on our listings are grouped together, every mattress we list sits in one place, and our mattress guides cover firmness and the rest of the choice.