Having enough space to relax in is hugely important to the quality of your sleep. A king mattress is the most popular size in the UK. But don’t think there is just one version, in fact there are two. We also sell the slightly larger special size euro king to ensure customers with continental bed bases or frames measuring 160cm x 200cm find their perfect mattress too. Scroll to the foot of this page for more tips to help you pick the right option.