Although there is a surprising variety of pillow sizes, standard and king are the most popular. A king cushion is 20 inches by 36 inches, compared to a standard pillow’s 20 inches by 26 inches. Queen, travel, and child pillows are among the several pillow sizes.
A king pillow might provide extra space if you alternate between sleeping on your back and your side at night. King size is generally the best pillow size as you can roll left and right to support your neck and head better. Remember that if you plan to use the pillow for sleeping and not just as decoration, you should choose one with the appropriate firmness and support.