A span is a Biblical unit of measurement equal to 8.75 inches or 22.2 centimeters.

A span is determined by the measure of a stretched hand, from fingertip to fingertip.  Like the cubit, this is a relative measurement. 

A span is the measure of a half cubit.  It is not mentioned often in the Old Testament.  Four of the seven times it is used is in reference to the dimensions of the high priest's breastplate.