Table 2. Units, constants and conversion factors.

Table 2. Units, constants and conversion factors.
ångström (Å)	0.1 nanometre*
astronomical unit (AU or a.u.)	1.459 789 0x10⁸ kilometres*
centimetre (cm)	0.3937 inches
electron volt (eV)	1.6022x10^-19 joules
foot (ft)	30.48 centimetres*
inch (in)	2.54 centimetres*
kilogram (kg)	2.2046 pounds
kilometre (km)	0.6214 miles
light year (l.y.)	9.4605x10¹² kilometres = 0.306 60 parsec
micron (m)	1 micrometre = 10^-6 metres*
mile (mi)	1.6093 kilometres
nanometre (nm)	10^-9 metres*
parsec (pc)	3.0857x10¹³ kilometres = 3.261 61 light years
radian	57°.295 78
speed of light (c)	299,792.458 kilometres per second
tonne (t)	1,000 kilograms*
* These conversion factors are exact; other values are approximations to the accuracy given