Unit conversion is refers to conversion factors between different units of measurement for the same quantity.

Area Conversion

From To Value
mm2 m2 1E-6
cm2 m2 1E-4
hectare m2 1E4
km2 m2 1E6
in2 m2 6.4516E-4
ft2 m2 9.290304E-2 (144 in2)
yd2 m2 8.3612736E-1 (9 ft2)
rood m2 1.01171E3 (1210 yd2)
acre m2 4.0468564224E3 (4840 yd2)
mile2 m2 2.58998811E6 (640 acres)

Distance Conversion

From To Value
millimetre (mm) metre (m) 1E-3
centimetre (cm) m 1E-2
kilometre (km) m 1E3
inch (in) m 2.54E-2
foot (ft) m 3.048E-1 (12 in)
yard (yd) m 0.9144 exactly (3 ft)
fathom m 1.8288 (2 yd)
chain m 2.01168E1 (22 yd)
furlong m 2.01168E2 (10 chains, 220 yd)
cable - not precisely defined, 608ft (1/10 UK nautical mile) or 720 ft (120 fathoms)
mile m 1.609344E3 (1760 yd)
nautical mile (UK) m 1.853184E3 (6080 ft)
nautical mile (international) (n mile) m 1.852E3
league - not precisely defined, about 3 miles
astronomic(al) unit (AU) m 1.49597870E11
light year (l.y.) m 9.4607E15
parsec (pc) m 3.0857E16

Unit Symbols

Symbol US-Name
A amp (ampere)
C coul (coulomb)
dyn dyne
erg erg
F farad
G gauss
g gm (gram)
H henry
Hz hz (hertz)
J joule
K degC (kelvin)
kg kg (kilogram)
l liter
m m (meter)
MHz mhz (megahertz)
ml ml (milliliter)
Mx maxwell
N nt (newton)
Oe oe (oersted)
P poise
Pa pascal
s s (sec, second)
St stoke
T tesla
V volt
W watt
Wb weber
Ohm (Omega) ohm
a0 Bohr radius (bohrradius)
alpha reciprocal fine structure constant
amu atomic mass unit
au astronomical unit
c speed of light in vacuum
e elementary charge
epsilon permittivity of vacuum (permittivity)
faraday Faraday constant
force acceleration of gravity
gammae electron gyromagnetic ratio
gammap proton gyromagnetic ratio (in water)
ge electron Lande factor (g value)
gH proton Lande factor
grav acceleration of gravity (same as force)
Grav gravitational constant (gravity)
h Planck constant (planckconstant)
hartree atomic energy unit
hbar h/2 pi (hquer)
k Boltzmann constant (boltzmannconstant)
lambdac Compton wavelength (comptonwavelength)
me electron rest mass (electronmass)
mn neutron rest mass (neutronmass)
mp proton rest mass (protonmass)
mole equal to Avogadro's number (pure number!)
Mol same as mole
mu permeability of vacuum (permeability)
muB Bohr magneton (mub, bohrmagneton)
mun nuclear magneton (muN, nuclearmagneton)
NA Avogadro's number (unit /mol)
nue electron Larmor frequency factor
nup proton Larmor frequency factor
pi 3.14159... (Ludolf's number)
R gas constant
Vmol molar volume