A span (SafE) is a basic D'ni unit of linear measurement. If you create a pendulum in the D'ni Cavern with a period of 5 prorahntee, twice the length of that pendulum is 5 spans.


One span is equal to:

  • 15.8 feet
  • 4.82 meters


The Book of Ti'ana contains rough estimates for the length of a span, but they are inconsistent and overall inaccurate.

The KI in Uru uses a distance of 16 feet for one span because it is a simple multiple of Plasma’s underlying foot-based measurement system.