Pianists' hand spans vary greatly!
There is a very wide variation in the hand spans of pianists. Hand spans among adult men and women can vary by as much as 5 inches (12.7 cm).
The available data indicate that, on average, the hand spans of adult male (thumb to fifth finger) are about one inch (or 2.5 centimetres) greater than those of adult females. This means men can reach, on average, more than one extra white key on the current keyboard.
An important benchmark separating ‘small’ from ‘large’ hands is a span of 8.5 inches (21.6 cm). Up to this point, the pianist cannot normally play a tenth, and more importantly, fast passages of octaves and large chords can be uncomfortable and involve pain or tension. From the available data, we can estimate that about 76% of adult men have hand spans that can reach 8.5 inches or more. This leaves about 24% of men who cannot play a tenth. For women, the situation is much worse, as an estimated 87% of adult females do not have hands large enough to play a tenth.
Please explore the information available from these pages:
Pianists’ hand spans – Australian study
Hand span versus interval reach