Go ahead and spread out while you sleep on a California king size mattress from BJ's Wholesale Club. These extra-large mattresses are 84" by 72", adding plenty more space to your bed for comfortable and restful sleeping or just relaxing. Discover a wide range of big mattress brands like Sealy, Cradlesoft, Contour and many other industry-leading names, all priced low exclusively for Club Members. This large collection has a variety of different styles, designs and even colors to make it easy for you to find your ideal California king size bed. Innerspring mattresses offer exceptional full-body support with ease of movement, while memory foam flexes and molds to your body to relieve stress on common pressure points. Hoping for a cooler or cleaner mattress? Go for a California king with advanced cooling gel, or one finished with easy-to-clean covers. Shop BJ's Wholesale Club today for an affordable California king mattress.