Convert between Span (cloth) and other Length units.

Span (cloth)
	Atomic unit of length
	Aln
	Angstrom
	Arpent
	Astronomical unit
	Attometer
	Barleycorn
	Bohr radius
	Caliber
	Centiinch
	Centimeter
	Chain
	Chain (US survey)
	Cubit (Greek)
	Cubit (UK)
	Decimeter
	Dekameter
	Earth's distance from sun
	Earth's equatorial radius
	Earth's polar radius
	Electron radius (classical)
	Ell
	Exameter
	Famn
	Fathom
	Fathom (US survey)
	Femtometer
	Fermi
	Finger (cloth)
	Fingerbreadth
	Foot
	Foot (US survey)
	Furlong
	Furlong (US survey)
	Gigameter
	Hand
	Handbreadth
	Hectometer
	Inch
	Inch (US survey)
	Ken
	Kilometer
	Kiloparsec
	Kiloyard
	League
	League (statute)
	Light year
	Link
	Link (US survey)
	Long cubit
	Long reed
	Megameter
	Megaparsec
	Meter
	Microinch
	Micrometer
	Micron
	Mil
	Mile
	Mile (Roman)
	Mile (statute)
	Mile (US survey)
	Millimeter
	Nail (cloth)
	Nanometer
	Nautical league (int.)
	Nautical league (UK)
	Nautical mile (international)
	Nautical mile (UK)
	Parsec
	Perch
	Petameter
	Pica
	Picometer
	Planck length
	Point
	Pole
	Reed
	Rod
	Rod (US survey)
	Roman actus
	Rope
	Russian archin
	Sun's radius
	Terameter
	Twip
	Vara castellana
	Vara conuquera
	Vara de tarea
	X-unit
	Yard