Quantity	Symbol	Value	Units
Avogadro's Number	NA	6.0221367e23	mol-1
Boltzmann's Constant	k	1.380658e-23	J/K
Electron Charge Magnitude	e	1.60217733e-19	C
Mass of Electron	me	9.1093897e-31	kg
Mass of Neutron	mn	1.6749286e-27	kg
Mass of Proton	mp	1.6726231e-27	kg
Permeability of Free Space	muo	4 pi 1.0e-7	T m/A
Permittivity of Free Space	epso	8.854187817e-12	(C/m)2N
Planck's Constant	h	6.62606891e-34	J s
Rydberg Constant	R	1.097e7	m-1
Speed of Light in Vacuum	c	2.99792458e8	m/s
Universal Gravitational Constant	G	6.67259e-11	N (m/kg)2
Multiplicative Conversions
Parameter	From	To	Factor
Length	in	cm	2.54
	ft	m	0.3048
	mi	ft	5280
	m	ft	3.281
	km	mi	0.6214
	angstrom	m	1.0e-10
Mass	slug	kg	14.59
	kg	grams	1000
	amu	kg	1.6605e-27
Time	day	min	1440
	day	hr	24
	day	sec	8.64e4
	yr	days	365.24
	yr	sec	3.156e7
Speed	mi/hr	km/hr	1.609
	mi/hr	ft/s	1.467
	mi/hr	m/s	0.4470
	km/hr	mi/hr	0.6214
	km/hr	m/s	0.2778
	km/hr	ft/s	0.9113
Force	lb	N	4.448
	N	dyne	1.0e5
	N	lb	0.2248
	J	ft lb	0.7376
	J	erg	1.0e7
	kcal	J	4186
	Btu	J	1055
	kWh	J	3.6e6
	eV	J	1.602e-19
Power	hp	ft lb/s	550
	hp	W	745.7
	W	ft lb/s	0.7376
Pressure	Pa	N/m2	1
	Pa	lb/in2	1.450e-4
	lb/in2	Pa	6.895e3
	atm	Pa	1.013e5
	atm	bar	1.013
	atm	lb/in2	14.70
	atm	torr	760
Volume	liter	m3	1.0e-3
	liter	cm3	1000
	liter	ft3	0.03531
	ft3	m3	0.02832
	ft3	U.S. gallons	7.481
	U.S.gallon	m3	3.785e-3
	U.S. gallons	ft3	0.1337
Angle	radian	degree	57.30
	degree	radian	0.01745