The bed.chat checklist says a UK King (150 × 200 cm) is about the size of a US Queen (60 × 80 in, about 152 × 203 cm). It says to compare sizes in centimetres, not names.
US mattress sizes
The Sleep Foundation, a review site that earns from shop links, lists the standard US sizes in inches (width x length):
- Twin: 38 x 75 in
- Twin XL: 38 x 80 in
- Full: 54 x 75 in
- Queen: 60 x 80 in
- King: 76 x 80 in
- California King: 72 x 84 in
Consumer Reports gives the US queen size as 60 x 80 inches. Consumer Reports says the queen is the most commonly sold size and the size it tests. The Sleep Foundation says those over 6 feet tall will want to consider a bed with at least 80 inches of length (Twin XL, Queen, King and California King).
UK mattress sizes
Which? says UK adult mattresses come in 10 different sizes, not just single, double and king. The common ones, in centimetres, are:
- Small single: 75 x 190 cm
- Single: 90 x 190 cm (approximately 3ft x 6ft 3in)
- A small double mattress measures 120 x 190 cm
- Double: 135 x 190 cm, the second most popular size
- King: 150 x 200 cm
- Super king: 180 x 200 cm, the size of two standard singles side by side
Where the names clash
Which? says a UK king-size mattress measures 150 x 200 cm. The Sleep Foundation lists a US King as 76 x 80 in.
"Queen" clashes too. Consumer Reports gives the US queen as 60 x 80 inches. Which? says a UK queen-size mattress is effectively a small double mattress measuring 120 x 190 cm.
European sizes add a third set. Which? says a European king measures 160 x 200 cm, and that European sizes are slightly wider than UK ones, so a UK mattress bought for a bed built for a European mattress will be too small.
Depth, bedding and frames
Width and length are not the whole story. Which? says there is no standard mattress depth, with tested mattresses ranging from under 20 cm to over 30 cm deep. Which? also says sheet and duvet sizes vary by brand, so double-check the dimensions before you buy bedlinen.
If you are thinking about an electric bed, Which? says adjustable beds tend to be a bit wider than standard beds, so check one will fit your bedroom before you buy.
Other countries
For Canada, Australia, New Zealand and Ireland as well as the US and UK, the bed.chat size tool lists mattress sizes by country in centimetres and inches, with the source of each figure.
Before you order
The bed.chat checklist gives two checks for size:
- Compare sizes in centimetres, not names.
- Measure the frame you have.
For a personal answer, Bed Fit, the chooser on the bed.chat home page, tells you the size for your country along with the mattress type and firmness range.