Ångstrom  Å  1e10 m  i Ångstrom
 Metric unit of length, equal to 0.1 nanometer or 10^{10} meter. Angstroms are used most often to measure the wave length of light waves.

micron  μm  1e06 m  
millimeter  mm  1e03 m  
centimeter  cm  1e02 m  
meter  m  1 m  i meter
 SI Base unit of distance

kilometer  km  1e+03 m  
line  li  2.11667e03 m  i line
 Traditional unit of distance equal to 1/12 inch (about 2.1167 millimeters)

inch  "  2.54e02 m  i inch
 1 in = (1/12) ft = 0.0254 m.
Before 1963 the imperial inch was equal to 25.399 965 mm For more info see yard, foot

hand  hand  1.016e01 m  i hand
 Traditional unit of distance, now used mostly to measure the height of horses. One hand equals 4 inches, 1/3 foot, or 10.16 centimeters

link  link  2.01168e01 m  i link
 Traditional unit of distance used by surveyors, equal to 0.01 chain. In Britain, one link is exactly 0.66 feet, or 7.92 inches, or approximately 20.12 centimeters

foot  ft  3.048e01 m  i foot
 The UK and USsystem of length is based on the yard:
1 foot = 12 inches 1 yard = 3 feet 1 chain = 22 yards 1 furlong = 10 chains 1mile = 8 furlongs 1 foot is exactly 0.3048 m

yard  yd  9.144e01 m  i yard
 One yard is officially equal to exactly 91.44 centimeters or 0.9144 meter; this definition was adopted in the U.S. in 1959 and in Britain by the Weights and Measures Act of 1963.

rod  rd  5.0292 m  i rod
 A traditional unit of distance equal to 5.5 yards (16 feet 6 inches or exactly 5.0292 meters).

chain  ch  2.01168e+01 m  i chain
 Unit of distance formerly used by surveyors. The traditional British surveyor s chain is 4 rods long that s equal to exactly 1/80 mile, 1/10 furlong, 22 yards, or 66 feet (20.1168 meters)

furlong  fur  2.01168e+02 m  i furlong
 Traditional unit of distance. A furlong equals 40 rods, which is exactly 10 chains, 220 yards, 660 feet, or 1/8 mile. One furlong is exactly 201.168 meters

mile (statute)  mile  1.60934e+03 m  i mile (statute)
 1 (statute) mile = 1760 yd
For more info see foot

mile (nautical)  nmi, naut mi  1.852e+03 m  i mile (nautical)
 Unit of distance used primarily at sea and in aviation. In 1929 an international conference in Monaco redefined the nautical mile to be exactly 1852 meters or 6076.115 49 feet, a distance known as the international nautical mile. The international nautical mile equals about 1.1508 statute miles.

league  league  4.82803e+03 m  i league
 Traditional unit of distance. In the U.S. and Britain, standard practice is to define the league to be 3 statute miles (about 4828.03 meters) on land

parsec  pc  3.08568025e+16 m  i parsec
 The parsec is a unit of length used in astronomy. It stands for "parallax of one arc second". It is based on the method of trigonometric parallax, one of the most ancient and standard methods of determining stellar distances. The parallax of a star is half angular distance a star appears to move against the celestial sphere due to the orbit of the Earth around the Sun. Equivalently, it is the angle subtended at a star by the radius of the Earth's orbit. One parsec is defined to be the distance from the Earth of a star that has a parallax of 1 arcsecond
