Convert from span to metre

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

Unit Definition (metre)
The meter is the basic unit of length adopted under the Systeme International d'Unites (approximately 1.094 yards). The meter is also the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second by definition