Units of measure

Name	Symbol	Coefficient	Name	Symbol	Coefficient
exa	E	[[$ 10^{18}$]]	deci	d	[[$10^{-1}$]]
peta	P	[[$ 10^{15}$]]	centi	c	[[$10^{-2}$]]
tera	T	[[$ 10^{12}$]]	milli	m	[[$10^{-3}$]]
giga	G	[[$10^{9}$]]	micro	μ	[[$10^{-6}$]]
mega	M	[[$10^{6}$]]	nano	n	[[$10^{-9}$]]
kilo	k	[[$10^{3}$]]	pico	p	[[$10^{-12}$]]
hecto	h	[[$10^{2}$]]	femto	f	[[$10^{-15}$]]
deca	da	[[$10^{1}$]]	atto	a	[[$10^{-18}$]]

Additional units

Quantity	Unit	Symbol	Equivalency
time	minute	min	1 min = 60 s
	hour	h	1 h = 60 min
	day	d	1 d = 24 h
	year	a	1 a [[$\approx $]] 365 d
plane angle	degree	°	1° = 60'
	minute	'	1' = 60''
	second	''
volume	litre	l	1 l = 1 dm3
mass	tonne	t	1 t = 1000 kg
	atomic mass unit	u	1 u = 1.6605402 [[$\cdot$]] 10-27 kg
length	astronomical unit	AU	1 AU = 0.1495979 [[$\cdot$]] 1012 m
	parsec	pc	1 pc = 30.85678 [[$ \cdot$]] 1015 m

Conversion factors

Length	1 ″ = 1 in = 1 inch = 25.40 mm
	1 ′ = 1 ft = 1 foot = 0.3048 m
	1 yd = 1 yard = 0.9144 m
	1 mi = 1 mile = 1.609344 km
	1 NM = 1 M = 1 nautical mile = 1852 m
	1 light year = 9.46055 [[$ \cdot$]] 1015 m
	1 AU = astronomical unit = 149.5979 [[$ \cdot $]] 109 m
Mass	1 ct = 1 carat = 0.2 g
	1 u = 1.6605402 [[$\cdot$]] 10-27 kg
	1 lb = 1 pound = 0.4536 kg
	1 oz = 1 ounce = 28.35 g
Plane angle	1° = 2[[$ \pi / $]]360 rad
Area	1 b = 1 barn = 10-28 m2
	1 acre = 4.0469 [[$ \cdot $]] 103 m2
Volume	1 l = 1 dm3 = 0.001 m3
	1 bbl = 1 barrel = 0.1589873 m3
	1 gal = 1 gallon (UK) = 4.546092 l
	1 gal = 1 gallon (US) =3.785412 l
Speed	1 knot = 1 NM/h = 1.852 km/h = 0.5144 m/s

Physical constants

Name	Symbol	Numeric value and unit
acceleration of free fall	[[$g$]]	[[$ \text{9.80665} $]] m/s2
light speed	[[$c$]]	[[$ \text{2.99792458}\cdot 10^{8}$]] m/s
electron mass	[[$m_e$]]	[[$ \text{9.1093897}\cdot 10^{-31}$]] kg
proton mass	[[$m_p$]]	[[$ \text{1.6726231} \cdot 10^{-27}$]] kg
neutron mass	[[$m_n$]]	[[$\text{1.6749286} \cdot 10^{-27}$]] kg