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SI BASE AND SUPPLEMENTARY UNIT NAMES AND SYMBOLS
Physical Quality	Name	Symbol
Length	meter	m
Mass	kilogram	kg
Time	second	s
Electric current	ampere	A
Thermodynamic temperature	kelvin	K
Amount of substance	mole	mol
Luminous intensity	candela	cd
Plane angle	radian	rad
Solid angle	steradian	sr

Temperature

Scientists commonly use the Celsius system. Although not recommended for scientific and technical use, earth scientists also use the familiar Fahrenheit temperature scale (°F). 1°F = 1.8°C or K. The triple point of H₂0, where gas, liquid, and solid water coexist, is 32°F.

To change from Fahrenheit (F) to Celsius (C): °C = (°F^-32)/(1.8)
To change from Celsius (C) to Fahrenheit (F): °F = (°C × 1.8) + 32
To change from Celsius (C) to Kelvin (K): K = °C + 273.15
To change from Fahrenheit (F) to Kelvin (K): K = (°F^-32)/(1.8) + 273.15

UNITS DERIVED FROM SI, WITH SPECIAL NAMES AND SYMBOLS
Derived Quantity	Name of SI Unit	Symbol for SI Unit	Expression in Terms of SI Base Units
Frequency	hertz	Hz	s-1
Force	newton	N	m kg s-2
Pressure, stress	Pascal	Pa	N m-2 =m-1 kg s-2
Energy, work, heat	Joule	J	N m =m2 kg s-2
Power, radiant flux	watt	W	J s-1 =m2 kg s-3
Electric charge	coulomb	C	A s
Electric potential, electromotive force	volt	V	J C-1 =m-2 kg s-3 A-1
Electric resistance	ohm	_	V A-1 =m2 kg s-3 A-2
Celsius temperature	degree Celsius	C	K
Luminous flux	lumen	lm	cd sr
Illuminance	lux	lx	cd sr m-2

UNITS USED WITH SI, WITH NAME, SYMBOL, AND VALUES IN SI UNITS
The following units, not part of the SI, will continue to be used in appropriate contexts (e.g., angtsrom):
Physical Quantity	Name of Unit	Symbol for Unit	Value in SI Units
Time	minute	min	60 s
	hour	h	3,600 s
	day	d	86,400 s
Plane angle	degree	°	(π/180) rad
	minute	′	(π/10,800) rad
	second	"	(π/648,000) rad
Length	angstrom	Å	10^-10 m
Volume	liter	I, L	1 dm³ = 10^-3 m³
Mass	ton	t	1 mg = 10³ kg
	unified atomic mass unit	u (=m_a(¹²C)/12)	≅1.66054 × 10^-27 kg
Pressure	bar	bar	10⁵ Pa = 10⁵ N m^-2
Energy	electronvolt	eV (=ε × V)	≅1.60218 × 10^-19 J