There are different sizes of hockey pucks. The largest puck you can get is 3.5 inches (88 mm), generally only used in professional competitions. However, the most common size you will see is 3.25 inches (82 mm), suitable for a large table of 7 feet (2.1 m). The other two common sizes are 3 inches (76 mm) and 2.5 inches (63 mm), suitable for small tables.