Convert from finger to span

Unit Definition (finger)
The finger is a traditional unit of distance equal to 2 nails or 4.5 inches (11.43 centimeters). This unit represents the length of the middle finger, from the tip to the joint where the finger is attached to the hand.

Unit Definition (span)
Span is the width of a human hand, from the tip of the thumb to the tip of the pinky finger.