LENGTH (Full list)
system	unit	unit- code	abbrev- iation	notes	sample default conversion	combination output units
SI	megametre	Mm	Mm	US spelling: megameter	1.0 Mm (620 mi)
	kilometre	km	km	US spelling: kilometer	1.0 km (0.62 mi)	km mi
	metre	m	m	US spelling: meter	1.0 m (3 ft 3 in)	m ft m ftin
	centimetre	cm	cm	US spelling: centimeter	1.0 cm (0.39 in)	cm in
	millimetre	mm	mm	US spelling: millimeter	1.0 mm (0.039 in)	mm in
	micrometre	μm (um)	µm	US spelling: micrometer	1.0 µm (3.9×10−5 in)
	nanometre	nm	nm	US spelling: nanometer	1.0 nm (3.9×10−8 in)
non-SI metric	ångström	Å (angstrom)	Å		1.0 Å (3.9×10−9 in)
Imperial & US customary	mile	mi	mi		1.0 mi (1.6 km)	mi km
	furlong	furlong	(none)		1.0 furlong (660 ft; 200 m)
	chain	chain	(none)		1.0 chain (66 ft; 20 m)
	rod	rd	rd	For other names of this unit see the full list.	1.0 rd (17 ft; 5.0 m)
	fathom	fathom	(none)	assumes 1 fathom ≡ 6 ft	1.0 fathom (6.0 ft; 1.8 m)
	yard	yd	yd	assumes the international definition	1.0 yd (0.91 m)
	foot	ft (foot)	ft	code "foot" will show "foot" if plural. code "ft" will show "foot" or "feet" depending on value.	1.0 ft (0.30 m)	ftin (feet and inches) ft m (foot m)
	inch	in	in		1.0 in (25 mm)	in cm in mm
Other	nautical mile	nmi	nmi	the international standard nautical mile For other nautical miles see the full list.	1.0 nmi (1.9 km; 1.2 mi)
	parsec	pc	pc		1.0 pc (3.3 ly)
	light-year	ly	ly		1.0 ly (63,000 AU)
	astronomical unit	AU	AU		1.0 AU (150,000,000 km; 93,000,000 mi)