Visiting the websites of reputable mattress retailers is one way of finding legitimate size charts for the various mattress sizes, including queen-size beds. SleepTrain.com has an entire section dedicated to mattress education and includes a visual, comprehensive mattress size chart.
Sizes are approximate and may vary by manufacturer, which means that the best option is to refer to a mattress size chart that is specific to your mattress brand, CSGNetwork.com notes. The standard measurements for a queen-size mattress are 60 inches by 80 inches. Additional options are available, such as the California queen bed size and the expanded queen bed size. The California queen bed size is 60 inches by 84 inches. The expanded queen is 66 inches by 80 inches.