Your choice of mattress will set the tone for your entire day, so let’s make it a good one! For a roomy experience, you might consider one of the traditional king mattresses. But if what you want is an absolutely luxurious sleeping option, the spacious California king mattress is the one for you. Measuring in at an impressive minimum standard of 72-inches wide by 84-inches long, the California king mattress is the lengthiest and most substantial of them all. Shop Costco’s Cal king mattress selection now, and get started on a great night’s sleep.