The sizes of fungi vary greatly depending on the type of fungus. In general, most microscopic—or smaller—fungi are 2 to 10 micrometers (MGRm) in diameter and several tenths of an inch in length. The average size of fungi hyphae are 5 to 50 micrometers (MGRm) in length.

On the other hand, macroscopic mushrooms are much larger—especially the part that is visible, or the fruiting body, also called sporophores (see above about fruiting bodies). These range in size from 8 to 10 inches (20–25 centimeters) and heights of 10 to 12 inches (25–30 centimeters). Some of the larger fungi, such as the bracket fungi, can reach over 16 inches (40 centimeters) in diameter; even larger are some giant puff-balls, the largest measuring 5 feet (150 centimeters) in diameter.