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Last verified April 2026
California King and Standard King Dimensions: Exact Sizes, Centimetres, and International Equivalents
The question most buyers actually need answered: by exactly how many inches do these two sizes differ, and how does that compare to sizes sold in the UK, Europe, and Australia?
US Mattress Dimensions
| Size | Inches (W x L) | Centimetres | Square feet | Square inches |
|---|---|---|---|---|
| California King | 72 x 84 | 182.88 x 213.36 | 42.0 sq ft | 6,048 |
| Standard King | 76 x 80 | 193.04 x 203.20 | 42.2 sq ft | 6,080 |
| Queen | 60 x 80 | 152.40 x 203.20 | 33.3 sq ft | 4,800 |
| Twin XL | 38 x 80 | 96.52 x 203.20 | 21.1 sq ft | 3,040 |
| Full / Double | 54 x 75 | 137.16 x 190.50 | 28.1 sq ft | 4,050 |
| Twin | 38 x 75 | 96.52 x 190.50 | 19.8 sq ft | 2,850 |
Dimensions verified against ASTM F1566-18 and manufacturer spec sheets from Casper, Purple, Saatva, and Tempur-Pedic, April 2026.
Cal King is longer by
4"
84 vs 80 inches long
Standard King is wider by
4"
76 vs 72 inches wide
Area difference
32 sq in
Standard King is marginally larger
International Bed Sizes Compared
Expats, travellers, and anyone buying internationally need this. UK bed sizes are not equivalent to US bed sizes, despite sharing some terminology. This table has all six major sizes in one place.
| Name | Region | Inches (W x L) | Centimetres | Notes |
|---|---|---|---|---|
| California King | US | 72 x 84 | 182.88 x 213.36 | Longer, narrower than Standard King |
| Standard (Eastern) King | US | 76 x 80 | 193.04 x 203.20 | Wider, shorter than Cal King |
| Super King | UK | 70.87 x 78.74 | 180 x 200 | Narrower than both US Kings, shorter than Cal King |
| King | UK | 59.06 x 78.74 | 150 x 200 | Closer to US Queen. NOT equivalent to US King |
| King (continental) | EU | 62.99 x 78.74 | 160 x 200 | Varies by country. Between UK King and Queen |
| King | Australia | 72.05 x 80.31 | 183 x 204 | Nearly identical to US Standard King |
Key insight for expats and international buyers
A UK Super King (180x200cm) is narrower than both US Kings and shorter than a California King. Do not assume UK bedding will fit a US Cal King. An Australian King (183x204cm) is almost identical to a US Standard King and may be the closest international equivalent.
Per-Person Sleep Surface Math
Width per person is the dimension that actually determines whether you feel crowded. Here is the math across common household configurations.
| Setup | Cal King (72" wide) | Standard King (76" wide) |
|---|---|---|
| Solo sleeper | 72" entire width | 76" entire width |
| Two adults | 36" per person | 38" per person |
| Two adults + small dog (12") | 30" per person | 32" per person |
| Two adults + medium dog (18") | 27" per person | 29" per person |
| Two adults + one child (24") | 24" per person | 26" per person |
Note: 38 inches is roughly the width of an American twin mattress. 36 inches is roughly the width of a US military cot. Width matters more than most buyers realise.
Diagonal Lengths (Relevant for Stairs)
Cal King diagonal: ~110.6 inches (9.2 ft)
Standard King diagonal: ~110.3 inches (9.2 ft)
Both are too wide for a typical 36-inch-wide residential staircase at a 45-degree rotation. See shipping and moving guide for the full staircase reality.