Online Encyclopedia

Categories: Units of measure

Conversion of units

This article lists conversion factors between a number of units of measurement.

Key:
≡ definition
= exactly equal to
≈ approximatively equal to

Contents

1 Length

2 Area

3 Volume

4 Angle

5 Mass

6 Time

7 Speed

8 Acceleration

9 Force

10 Pressure

11 Energy or Work

12 Power

13 Angular momentum

14 Electric current

15 Electric charge

16 Electromotive force

17 Electrical resistance

18 Kinematic viscosity

19 Temperature

20 See also

21 External links

Length

Name of unit	Symbol	Relation to SI units
Length, l
metre (SI base unit)	m	≡ m
Fermi	fm	≡ 10^-15 m = 1 fm
x unit; siegbahn	xu	≈ 1.0021×10^-13 m
stigma		≡ 1×10^-12 m = 1 pm
Bohr radius	a₀; b	≡ α/(4πR_∞) ≈ 5.291 772 083×10^-11 ± 19×10^-20 m
atomic unit of length	au	≡ a₀ ≈ 5.291 772 083×10^-11 ± 19×10^-20 m
ångström	Å	≡ 10^-10m = 0.1 nm
micron	μ	≡ 10^-6m = 1 μm
twip	twp	≡ 1/1440 in ≈ 1.763 889×10^-5 m
mil; thou	mil	≡ 10^-3 in = 2.54×10^-5 m
mickey		≡ 1/200 in = 1.27×10^-4 m
calibre	cal	≡ 1/100 in = 0.254 mm
point (ATA )	pt	≡ 0.013837 in = 0.351 459 8 mm
point (PostScript)	pt	≡ 1/72 in ≈ 0.352 778 mm
point (metric)	pt	≡ 3/8 mm = 0.375 mm
point (Didot; European)	pt	≡ 0.376 065 mm
line	ln	≡ 1/12 in ≈ 2.116 667 mm
line (Paris) ["ligne"]	l	≡ 1/12 p = 1/443.296 m ≈ 2.255 829 mm
line (Quebec) ["ligne"]	l (Qc)	≡ 1/12 p (Qc) = 2.255 837 5 mm
barley corn		≡ 1/3 in ≈ 8.466 667 mm
finger		≡ 7/8 in = 22.225 mm
inch	in	≡ 1/36 yd = 25.4 mm
U.S. survey inch	in	≡ 1/12 U.S. survey foot = 100/3937 m ≈ 25.400051 mm
inch (Paris) ["pouce"]	p	≡ 1/12 P = 1/(36 + 11.296/12) m ≈ 27.069 949 mm
inch (Quebec) ["pouce"]	p (Qc)	≡ 1/12 P (Qc) = 27.070 05 mm
stick		≡ 2 in = 50.8 mm
nail (cloth)		≡ 2 1/4 in = 57.15 mm
palm		≡ 3 in = 76.2 mm
hand		≡ 4 in = 0.1016 m
finger (cloth)		≡ 4 1/2 in = 0.1143 m
span		≡ 6 in = 0.1524 m
link (Gunter's)	lnk	≡ 66/100 ft = 0.201 168 m
span (cloth)		≡ 9 in = 0.2286 m
quarter		≡ 1/4 yd = 0.2286 m
link (Ramden's; Engineer's)	lnk	≡ 1 ft = 0.3048 m
foot (Clarke's; Cape)	ft (Cla)	≈ 0.304 797 265 4 m
foot (Sear's)	ft (Sear)	≈ 0.304 799 47 m
foot (Indian)	ft Ind	≈ 0.304 799 514 m
foot (Benoît)	ft (Ben)	≈ 0.304 799 735 m
foot	ft	≡ 12 in = 0.3048 m
foot (American; U.S. Survey)	ft (US)	≡ 1200/3937 m ≈ 0.304 800 610 m
foot (Paris) ["pied"]	P	≡ 1/(3 + 11.296/144) m ≈ 0.324 839 385 m
foot (Quebec) ["pied"]	P (Qc)	≡ 1.06575 ft = 0.324 840 6 m
cubit		≡ 18 in = 0.4572 m
pace		≡ 2 1/2 ft = 0.762 m
yard	yd	≡ 3 ft = 0.9144 m
ell	ell	≡ 45 in = 1.143 m
fathom	fm	≡ 6 ft = 1.8288 m (sometimes ≡ 1/1000 NM = 1.852 m)
rod; pole; perch	rd	≡ 16 1/2 ft = 5.0292 m
rope	rope	≡ 20 ft = 6.096 m
chain (Gunter's)	ch	≡ 66 ft = 20.1168 m
chain (Ramden's; Engineer's)	ch	≡ 100 ft = 30.48 m
arpent (Paris)	arp	≡ 180 P = 25 920/443.296 m ≈ 58.471 089 m
arpent (Quebec)	arp (Qc)	≡ 180 P (Qc) = 58.471 308 m
cable length (International)		≡ 1/10 NM = 185.2 m
cable length (Imperial)		≡ 608 ft = 185.3184 m
furlong	fur	≡ 660 ft = 201.168 m
cable length (U.S.)		≡ 720 ft = 219.456 m
mile	mi	≡ 1760 yd = 5280 ft = 1609.344 m
mile (American; Statute; U.S. Survey)	mi	≡ 5280 ft (US) = 5280×1200/3937 m ≈ 1609.347 219 m
nautical mile	NM; nm	≡ 1852 m
nautical mile (Admiralty)	NM (Adm); nm (Adm)	≡ 6080 ft = 1853.184 m
geographical mile	mi	≡ 6082 ft = 1853.7936 m
telegraph mile	mi	≡ 6087 ft = 1855.3176 m
league	lea	≡ 3 mi = 4828.032 m
statute league	lea	≡ 3 mi (US) ≈ 4828.041 656 m
nautical league	NL; nl	≡ 3 NM = 5556 m
light-second		≡ 2.997 924 58×10⁸ m
light-minute		≡ 60 light-seconds = 1.798 754 748×10¹⁰ m
astronomical unit	AU	= 149 597 870.691 ± 0.030 km
spat	S	≡ 10¹² m = 1 Tm
light-hour		≡ 60 light-minutes = 1.079 252 848 8×10¹² m
light-day		≡ 24 light-hours = 2.590 206 837 12×10¹³ m
light-year	l.y.	≡ c₀×86 400×365.25 = 9.460 730 472 580 8×10¹⁵ m
parsec	pc	≈ 180×60×60/π AU ≈ 206 264.806 25 AU = 3.261 563 776 9 ± 6×10^-10 light-years = 3.085 677 581 3×10¹⁶ ± 6×10⁶ m

Area

Name of unit	Symbol	Relation to SI units
Area, A
square metre (SI unit)	m²	≡ 1 m × 1 m
barn	b	≡ 10^-28 m²
circular mil; circular thou	circ mil	≡ π/4 mil² ≈ 5.067 075×10^-10 m²
square mil; square thou	sq mil	≡ 1 mil² = 6.4516×10^-10 m²
circular inch	circ in	≡ π/4 in² ≈ 5.067 075×10^-4 m²
square inch	sq in	≡ 1 in² = 6.4516×10^-4 m²
board	bd	≡ 1 in × 1 ft = 7.741 92×10^-3 m²
square link	sq lnk	≡ 1 lnk² = 4.046 856 422 4×10^-2 m²
square foot	sq ft	≡ 1 ft² = 9.290 304×10^-2 m²
square yard	sq yd	≡ 1 yd² = 0.836 127 36 m²
cord		≡ 192 bd = 1.486 448 64 m²
boiler horsepower equivalent direct radiation	bhp EDR	≡ 1 sq ft × 1 bhp / 240 BTU_IT/h ≈ 12.958 174 m²
square rod/pole/perch	sq rd	≡ 1 rd² = 25.292 852 64 m²
are	a	≡ 100 m²
square chain	sq ch	≡ 1 ch² = 404.685 642 24 m²
rood	ro	≡ 1/4 ac = 1011.714 105 6 m²
acre	ac	≡ 10 sq ch = 4840 sq yd = 4046.856 422 4 m²
hectare	ha	≡ 10 000 m² = 0.01 km²
yardland		≡ 30 ac = 1.214 056 926 72×10⁵ m²
hide		≡ 100 ac = 4.046 856 422 4×10⁵ m²
square kilometre	km²	≡ 1 km² = 10⁶ m²
square mile; section	sq mi	≡ 1 mi² = 2.589 988 110 336×10⁶ m²
square statute mile; square U.S. Survey mile	sq mi	≡ 1 mi (US)² ≈ 2.589 998×10⁶ m²
township		≡ 36 sq mi (US) ≈ 9.323 994×10⁷ m²
barony		≡ 4000 ac = 1.618 742 568 96×10⁷ m²

Volume

Name of unit	Symbol	Relation to SI units
Volume, V
cubic metre (SI unit)	m³	≡ 1
litre	L	≡ 1 dm³
lambda	λ	≡ 1 mm³ = 1 μL
dram (Imperial fluid); Imperial fluidram	fl dr	≡ 1/8 fl oz = 3.551 632 812 5 mL
dram (U.S. fluid); U.S. fluidram	fl dr	≡ 1/8 US fl oz = 3.696 691 195 312 5 mL
teaspoon (Canadian)	tsp	≡ 1/6 fl oz ≈ 4.735 510 416 667 mL
teaspoon (U.S.)	tsp	≡ 1/6 US fl oz = 4.928 921 595 mL
teaspoon (metric)		≡ 5 mL
tablespoon (Canadian)	tbsp	≡ 1/2 fl oz = 14.206 531 25 mL
tablespoon (U.S.)	tbsp	≡ 1/2 US fl oz = 14.786 764 782 5 mL
tablespoon (metric)		≡ 15 mL
cubic inch	cu in	≡ 1 in³ = 16.387 064 mL
tablespoon (Imperial)	tbsp	≡ 5/8 fl oz = 17.758 164 062 5 mL
fluid ounce (Imperial)	fl oz (Imp)	≡ 1/160 gal (Imp) = 28.413 062 5 mL
fluid ounce (U.S.)	fl oz (US)	≡ 1/128 gal (US) = 29.573 529 562 5 mL
cup (Canadian)	c (CA)	≡ 8 fl oz (Imp) = 227.3045 mL
cup (U.S.)	c (US)	≡ 1/16 gal (US) = 236.588 236 5 mL
cup (Metric)	c	≡ 250 mL
pint (U.S. fluid)	pt (US fl)	≡ 1/8 gal (US) = 473.176 473 mL
pint (U.S. dry)	pt (US dry)	≡ 1/4 bu (US lvl) = 550.610 471 357 5 mL
pint (Imperial)	pt (Imp)	≡ 1/8 gal (Imp) = 568.261 25 mL
quart (U.S. fluid)	qt (US)	≡ 1/4 gal (US fl) = 0.946 352 946 L
quart (U.S. dry)	qt (US)	≡ 1/32 bu (US lvl) = 1/4 gal (US dry) = 1.101 220 942 715 L
quart (Imperial)	qt (Imp)	≡ 1/4 gal (Imp) = 1.136 522 5 L
gallon (U.S. fluid)	gal (US)	≡ 231 cu in = 3.785 411 784 L
gallon (U.S. dry)	gal (US)	≡ 1/8 bu (US lvl) = 4.404 883 770 86 L
gallon (Imperial)	gal (Imp)	≡ 4.546 09 L
cubic foot	cu ft	≡ 1728 cu in = 28.316 846 592 L
bushel (U.S. dry level)	bu (US lvl)	≡ 2150.42 cu in = 35.239 070 166 88 L
bushel (Imperial)	bu (Imp)	≡ 8 gal (Imp) = 36.368 72 L
bushel (U.S. dry heaped)	bu (US)	≡ 1 1/4 bu (US lvl) = 44.048 837 708 6 L
barrel (U.S. oil)	bl	≡ 42 gal (US) = 158.987 294 928 L
barrel (Imperial)	bl (Imp)	≡ 36 gal (Imp) = 163.659 24 L
cubic yard	cu yd	≡ 27 cu ft = 0.764 554 857 984 m³
freight ton		≡ 40 cu ft = 1.132 673 863 68 m³
load		≡ 50 cu ft = 1.415 842 329 6 m³
register ton		≡ 100 cu ft = 2.831 684 659 2 m³

Angle

Name of unit	Symbol	Relation to SI units
Angle
radian	rad	≡ 1 rad
centesimal second of arc	"	≡ 1 gr/10000 ≈ 1.570 796 µrad
arcsecond	"	≡ 1°/3600 ≈ 4.848 137 µrad
centesimal minute of arc	'	≡ 1 gr/100 ≈ 0.157 080 mrad
minute of arc	'	≡ 1°/60 ≈ 0.290 888 mrad
angular mil	µ	≡ 2π/6400 rad ≈ 0.981 748 mrad
gradian; gon	gr	≡ 2π/400 rad = 0.9° ≈ 15.707 963 mrad
degree (of arc)	°	≡ π/180 rad ≈ 17.453 293 mrad
sign		≡ 30° ≈ 0.523 599 rad
octant		≡ 45° ≈ 0.785 398 rad
sextant		≡ 60° ≈ 1.047 198 rad
quadrant		≡ 90° ≈ 1.570 796 rad

Mass

Name of unit	Symbol	Relation to SI units
Mass, m
kilogram	kg	(SI base unit)
electron rest mass	m_e	≈ 9.109 381 88×10^-31 ± 72×10^-39 kg
atomic unit of mass	au	≡ m_e ≈ 9.109 381 88×10^-31 ± 72×10^-39 kg
unified atomic mass unit	amu	≈ 1.660 538 73×10^-27 ± 13×10^-35 kg
dalton	Da	≈ 1.660 902 10×10^-27 ± 13×10^-35 kg
gamma	γ	≡ 1 μg
point		≡ 1/100 kt (metric) = 2 mg
mite		≡ 1/20 gr = 3.239 945 5 mg
mite (metric)		≡ 1/20 g = 50 mg
grain	gr	≡ 64.798 91 mg
crith		≈ 89.9349 mg
carat (metric)	kt	≡ 200 mg
carat	kt	≡ 3 1/6 gr ≈ 205.196 548 333 mg
sheet		≡ 1/700 lb av = 647.9891 mg
scruple (avoirdupois)	s av	≡ 20 gr = 1.295 978 2 g
pennyweight	dwt; pwt	≡ 1/20 oz t = 1.555 173 84 g
dram (avoirdupois)	dr av	≡ 27 11/32 gr = 1.771 845 195 312 5 g
dram (apothecary; troy)	dr t	≡ 60 gr = 3.887 934 6 g
hyl (CGS unit)		≡ 1 gee × 1 g × 1 s²/m = 9.806 65 g
ounce (avoirdupois)	oz av	≡ 1/16 lb = 28.349 523 125 g
assay ton (short)	AT	≡ 1 mg × 1 sh tn ÷ 1 oz t ≈ 29.166 667 g
ounce (apothecary; troy)	oz t	≡ 31.103 476 8 g
assay ton (long)	AT	≡ 1 mg × 1 long tn ÷ 1 oz t ≈ 32.666 667 g
mark		≡ 8 oz t = 248.827 814 4 g
pound (troy)	lb t	≡ 5760 grains = 0.373 241 721 6 kg
pound (avoirdupois)	lb av	≡ 7000 grains = 0.453 592 37 kg
pound (metric)		≡ 500 g
clove		≡ 8 lb av = 3.628 738 96 kg
stone	st	≡ 14 lb av = 6.350 293 18 kg
hyl (MKSA unit)		≡ 1 gee × 1 kg × 1 s²/m = 9.806 65 kg
quarter (Imperial)		≡ 1/4 long cwt = 2 st = 28 lb av = 12.700 586 36 kg
slug; geepound	slug	≡ 1 gee × 1 lb av × 1 s²/ft ≈ 14.593 903 kg
bag		≡ 94 lb av = 42.637 682 78 kg
short hundredweight; cental	sh cwt	≡ 100 lb av = 45.359 237 kg
long hundredweight (U.S.) or hundredweight (Imperial)	long cwt or cwt	≡ 112 lb av = 50.802 345 44 kg
quintal (metric)		≡ 100 kg
wey		≡ 252 lb = 18 st = 114.305 277 24 kg (variants exist)
short quarter (U.S.)		≡ 1/4 sh tn = 226.796 185 kg
long quarter (U.S.)		≡ 1/4 long tn = 254.011 727 2 kg
kip	kip	≡ 1000 lb av = 453.592 37 kg
short ton	sh tn	≡ 2000 lb = 907.184 74 kg
tonne (mts unit)	t	≡ 1000 kg
long ton (U.S.) or ton (Imperial)	long tn or ton	≡ 2240 lb = 1016.046 908 8 kg
barge		≡ 22 1/2 sh tn = 20,411.656 65 kg

In physics, the pound of mass is sometimes written lbm to distinguish it from the pound-force (lbf). It should not be read as the mongrel unit "pound metre".

Time

Name of unit	Symbol	Relation to SI units
Time, t
second	s	(SI base unit)
Planck time		≡ √Gh/c⁵ ≈ 1.351 211 818×10^-43 s
atomic unit of time	au	≡ a₀/(α·c) ≈ 2.418 884 254×10^-17 s
svedberg	S	≡ 10^-13 s = 100 fs
shake		≡ 10^-8 s = 10 ns
sigma		≡ 10^-6 s = 1 μs
jiffy		≡ 1/60 s ≈ 16.666 667 ms (sometimes ≡ 1/100 s = 10 ms)
minute	min	≡ 60 s
hour	h	≡ 60 min = 3600 s
day	d	≡ 24 h = 86 400 s
week	wk	≡ 7 d = 604 800 s
fortnight		≡ 2 wk = 1 209 600 s
month (hollow)	mo	≡ 29 d = 2 505 600 s
month (full)	mo	≡ 30 d = 2 592 000 s
year (Calendar)	a	≡ 365 d = 31 536 000 s
year (Gregorian)	a	≡ 365.2425 d = 31 556 952 s
year (Julian)	a	≡ 365.25 d = 31 557 600 s
lustre; lustrum		≡ 5 a of 365 d = 1.5768×10⁸ s
octaeteris		≡ 8 a of 365 d = 2.522 88×10⁸ s
decade		≡ 10 a of 365 d = 3.1536×10⁸ s
enneadecaeteris; Metonic cycle		≡ 110 mo (hollow) + 125 mo (full) = 19 a of 365 d = 5.996 16×10⁸ s
Callippic cycle		≡ 441 mo (hollow) + 499 mo (full) = 76 a of 365.25 d = 2.398 377 6×10⁹ s
century (Calendar)		≡ 100 a of 365 d = 3.1536×10⁹ s
century (Julian)		≡ 100 a of 365.25 d = 3.155 76×10⁹ s
Hipparchic cycle		≡ 4 Callippic cycles - 1 d = 9.593 424×10⁹ s
millennium (Calendar)		≡ 1000 a of 365 d = 3.1536×10¹⁰ s
millennium (Gregorian)		≡ 1000 a of 365.2425 d = 3.155 695 2×10¹⁰ s
millennium (Julian)		≡ 1000 a of 365.25 d = 3.155 76×10¹⁰ s
Sothic cycle		≡ 1461 a of 365 d = 4.607 409 6×10¹⁰ s

Speed

Name of unit	Symbol	Relation to SI units
Speed, v
metre per second	m/s	≡ 1 m/s
foot per hour	fph	≡ 1 ft/h ≈ 8.466 667×10^-5 m/s
furlong per fortnight		≈ 1.663 095×10^-4 m/s
inch per minute	ipm	≡ 1 in/min ≈ 4.23 333×10^-4 m/s
foot per minute	fpm	≡ 1 ft/min = 5.08×10^-3 m/s
inch per second	ips	≡ 1 in/s = 2.54×10^-2 m/s
kilometre per hour	km/h	≡ 1 km/h ≈ 2.777 778×10^-1 m/s
foot per second	fps	≡ 1 ft/s = 3.048×10^-1 m/s
mile per hour	mph	≡ 1 mi/h = 0.447 04 m/s
statute mile per hour	mph	≈ 0.447 041 m/s
knot	kn	≡ 1 NM/h = 1.852 km/h ≈ 0.514 444 m/s
knot (Admiralty)	kn	≡ 1 NM (Adm)/h = 1.853 184 km/h ≈ 0.514 773 m/s
mile per minute	mpm	≡ 1 mi/min = 26.8224 m/s
mile per second	mps	≡ 1 mi/s = 1.609 344 km/s
speed of light in vacuum	c	≡ 2.997 924 58×10⁸ m/s

Acceleration

Name of unit	Symbol	Relation to SI units
Acceleration, a
metre per second squared	m/s²	≡ 1 m/s²
foot per hour per second	fph/s	≡ 1 ft/h·s ≈ 8.466 667×10^-5 m/s²
inch per minute per second	ipm/s	≡ 1 in/min·s ≈ 4.233 333×10^-4 m/s²
foot per minute per second	fpm/s	≡ 1 ft/min·s = 5.08×10^-3 m/s²
galileo	Gal	≡ 1 cm/s² = 0.01 m/s²
inch per second squared	ips²	≡ 1 in/s² = 2.54×10^-2 m/s²
foot per second squared	fps²	≡ 1 ft/s² = 3.048×10^-1 m/s²
mile per hour per second	mph/s	≡ 1 mi/h·s = 4.4704×10^-1 m/s²
knot per second	kn/s	≡ 1 kn/s ≈ 5.144 444×10^-1 m/s²
standard gravity	g	≡ 9.806 65 m/s²
mile per minute per second	mpm/s	≡ 1 mi/min·s = 26.8224 m/s²
mile per second squared	mps²	≡ 1 mi/s² = 1.609 344×10³ m/s²

Force

Name of unit	Symbol	Relation to SI units
Force, F
newton (SI unit)	N	≡ kg·m/s²
atomic unit of force	au	≡ m_e·α²·c²/a₀ ≈ 8.238 722 241×10^-8 N
dyne (cgs unit)	dyn	≡ g·cm/s² = 10^-5 N
gravet		≡ g × 1 g = 9.806 65 mN
poundal	pdl	≡ 1 lb·ft/s² = 0.138 254 954 376 N
ounce-force]]	ozf	≡ g × 1 oz = 0.278 013 850 953 781 2 N
pound-force	lbf	≡ g × 1 lb = 4.448 221 615 260 5 N
kilogram-force; kilopond; grave	kgf; kp	≡ g × 1 kg = 9.806 65 N
sthene (mts unit)	sn	≡ 1 t·m/s² = 1 kN
kip-force	kipf	≡ g × 1 kip = 4.448 221 615 260 5 kN
ton-force	tnf	≡ g × 1 sh tn = 8.896 443 230 521 kN

Pressure

Name of unit	Symbol	Relation to SI units
Pressure, P
pascal (SI unit)	Pa	≡ N/m² = kg/m·s²
barye (cgs unit)		≡ 1 dyn/cm² = 0.1 Pa
poundal per square foot	pdl/sq ft	≡ 1 pdl/sq ft ≈ 1.488 164 Pa
millimetre of water (4°C)	mmH2O	≡ 1000 kg/m³ × 1 mm × g = 9.806 65 Pa (= 1 kgf/m²)
pound per square foot	psf	≡ 1 lb/sq ft × g ≈ 47.880 259 Pa
centimetre of water (4°C)	cmH2O	≡ 1000 kg/m³ × 1 cm × g = 98.0665 Pa
torr	torr	≡ (101 325/760) Pa ≈ 133.322 Pa
millimetre of mercury	mmHg	≡ 13 595.1 kg/m³ × 1 mm × g = 133.322 387 415 Pa (≈ 1 torr)
inch of water (4°C)	inH2O	≡ 1000 kg/m³ × 1 in × g = 249.088 91 Pa
pièze (mts unit)	pz	≡ 1000 kg/m·s² = 1 kPa
centimetre of mercury	cmHg	≡ 13 595.1 kg/m³ × 1 cm × g = 1.333 223 874 15 kPa (≈ 10 torr)
foot of water (4°C)	ftH2O	≡ 1000 kg/m³ × 1 ft × g = 2.989 066 92 kPa
inch of mercury	inHg	≡ 13 595.1 kg/m³ × 1 in × g = 3.386 388 640 341 kPa
pound per square inch	psi	≡ 1 lb × g / 1 sq in ≈ 6.894 757×10³ Pa
foot of mercury	ftHg	&#8801 13 595.1 kg/m³ × 1 ft × g = 40.636 663 684 091 9 kPa
ton per square foot		≡ 1 sh tn × g / 1 sq ft ≈ 95.760 518 kPa
atmosphere (technical)	atm	≡ 1 kgf/cm² = 98.0665 kPa
bar	bar	≡ 10⁵ Pa
atmosphere (standard)	atm	≡ 101 325 Pa
kip per square inch	ksi	≡ 1 kipf/sq in ≈ 6.894757 MPa
kilogram-force per square millimetre	kgf/mm²	≡ 1 kgf/mm² = 9.806 65 MPa

Energy or Work

Name of unit	Symbol	Relation to SI units
Energy, E
joule (SI unit)	J	≡ N·m = kg·m²/s²
electronvolt	eV	≡ e × 1 V = 1/6.241 509 629 152 65×10¹⁸ J ≈ 1.602 176×10^-19 J
rydberg	Ry	≡ R_∞·h·c ≈ 2.179 872×10^-18 J
hartree	E_h	≡ m_e·α²·c² ≈ 4.359 744×10^-18 J (= 2Ry)
atomic unit of energy	au	≡ E_h ≈ 4.359 744×10^-18 J
erg (cgs unit)	erg	≡ 1 g·cm²/s² = 10^-7 J
foot-poundal	ft pdl	≡ 1 ft·pdl = 4.214 011 009 380 48×10^-2 J
cubic centimetre of atmosphere; standard cubic centimetre	cc atm; scc	≡ 1 atm × 1 cm³ = 0.101 325 J
inch-pound force	in lbf	≡ g × 1 lb × 1 in = 0.112 984 829 027 616 7 J
foot-pound force	ft lbf	≡ g × 1 lb × 1 ft = 1.355 817 948 331 400 4 J
calorie (20°C)	cal_20°C	≈ 4.1819 J
calorie (thermochemical)	cal_th	≡ 4.184 J
calorie (15°C)	cal_15°C	≡ 4.1855 J
calorie (International Table)	cal_IT	≡ 4.1868 J
calorie (mean)	cal_mean	≈ 4.190 02 J
calorie (4°C)	cal_4°C	≈ 4.2045 J
litre of atmosphere; standard litre	l atm; sl	≡ 1 atm × 1 L = 101.325 J
gallon of atmosphere (U.S.)	gal atm	≡ 1 atm × 1 gal (US) = 383.556 849 013 8 J
gallon of atmosphere (Imperial)	gal atm	≡ 1 atm × 1 gal (Imp) = 460.632 569 25 J
British thermal unit (thermochemical)	BTU_th	≡ 1 lb/g × 1 cal_th × 1 °F/°C = 9.489 152 380 4 ÷ 9 kJ ≈ 1.054 350 kJ
British thermal unit (ISO)	BTU_ISO	≡ 1.0545 kJ
British thermal unit (63°F)	BTU_63°F	≈ 1.0546 kJ
British thermal unit (60°F)	BTU_60°F	≈ 1.054 68 kJ
British thermal unit (59°F)	BTU_59°F	≡ 1.054 804 kJ
British thermal unit (International Table)	BTU_IT	≡ 1 lb/g × 1 cal_IT × 1 °F/°C = 1.055 055 852 62 kJ
British thermal unit (mean)	BTU_mean	≈ 1.055 87 kJ
British thermal unit (39°F)	BTU_39°F	≈ 1.059 67 kJ
Celsius heat unit (International Table)	CHU_IT	≡ 1 BTU_IT × 1 °C/°F = 1.899 100 534 716 kJ
cubic foot of atmosphere; standard cubic foot	cu ft atm; scf	≡ 1 atm × 1 cu ft = 2.869 204 480 934 4 kJ
kilocalorie; large calorie	kcal; Cal	≡ 1000 cal_IT = 4.1868 kJ
cubic yard of atmosphere; standard cubic yard	cu yd atm; scy	≡ 1 atm × 1 cu yd = 77.468 520 985 228 8 kJ
cubic foot of natural gas		≡ 1000 BTU_IT = 1.055 055 852 62 MJ
horsepower-hour	hph	≡ 1 hp (electrical imperial) × 1 h = 2.6856 MJ
Board of Trade Unit; kilowatt-hour	B.O.T.U.; kWh	≡ 1 kW × 1 h = 3.6 MJ
thermie	th	≡ 1 Mcal_IT = 4.1868 MJ
therm (U.S.)		≡ 100 000 BTU_59°F = 105.4804 MJ
therm (E.C.)		≡ 100 000 BTU_IT = 105.505 585 262 MJ
ton of TNT	tTNT	≡ 1 Gcal_th = 4.184 GJ
barrel of oil equivalent	bboe	≈ 5.8 MBTU_59°F ≈ 6.12 GJ
ton of coal equivalent	TCE	≡ 7 Gcal_th = 29.3076 GJ
ton of oil equivalent	TOE	≡ 10 Gcal_th = 41.868 GJ
quad		≡ 10¹⁵ BTU_IT = 1.055 055 852 62 EJ

Power

Name of unit	Symbol	Relation to SI units
Power, P
watt (SI unit)	W	≡ J/s = N·m/s = kg·m²/s³
lusec	lusec	≡ 1 L-µmHg/s ≈ 1.333 224×10^-4 W
foot-pound-force per hour	ft lbf/h	≡ 1 ft lbf/h ≈ 3.766 161×10^-4 W
standard cubic centimetre per minute	sccm	≡ 1 atm cm³/min = 1.688 75×10^-3 W
foot-pound-force per minute	ft lbf/min	≡ 1 ft lbf/min = 2.259 696 580 552 334×10^-2 W
standard cubic centimetre per second	sccs	≡ 1 atm cm³/s = 0.101 325 W
BTU (International Table) per hour	BTU_IT/h	≡ 1 BTU_IT/h ≈ 0.293 071 W
standard cubic foot per hour	scfh	≡ 1 atm cu ft/h = 0.797 001 244 704 W
foot-pound-force per second	ft lbf/s	≡ 1 ft lbf/s = 1.355 817 948 331 400 4 W
standard litre per minute	slpm	≡ 1 atm L/min = 1.688 75 W
calorie (International Table) per second	cal_IT/s	≡ 1 cal_IT/s = 4.1868 W
BTU (International Table) per minute	BTU_IT/min	≡ 1 BTU_IT/min ≈ 17.584 264 W
standard cubic foot per minute	scfm	≡ 1 atm cu ft/min = 47.820 074 682 24 W
square foot equivalent direct radiation	sq ft EDR	≡ 240 BTU_IT/h ≈ 70.337 057 W
standard litre per second	slps	≡ 1 atm L/s = 101.325 W
horsepower (metric)	hp	≡ 75 m kgf/s = 735.498 75 W
horsepower (U.S.)	hp (US)	≈ 735.7 W
horsepower (European electrical)	hp	≡ 736 W
horsepower (Imperial mechanical)	hp	≡ 550 ft lbf/s = 745.699 871 582 270 22 W
horsepower (Imperial electrical)	hp	≡ 746 W
horsepower (water)	hp (US)	≈ 746.043 W
ton of air conditioning		≡ 1 t × 1005 J/kg × 1 °F/K ÷ 10 min = 844.2 W
poncelet	p	≡ 100 m kgf/s = 980.665 W
BTU (International Table) per second	BTU_IT/s	≡ 1 BTU_IT/s = 1.055 055 852 62×10⁺³ W
standard cubic foot per second	scfs	≡ 1 atm cu ft/s = 2.869 204 480 934 4×10⁺³ W
ton of refrigeration (IT)		≡ 1 BTU_IT × 1 sh tn/lb ÷ 10 min/s ≈ 3.516 853×10⁺³ W
ton of refrigeration (Imperial)		≡ 1 BTU_IT × 1 lng tn/lb ÷ 10 min/s ≈ 3.938 875×10⁺³ W
boiler horsepower	bhp	≈ 34.5 lb/h × 970.3 BTU_IT/lb ≈ 9.810 657×10⁺³ W

Angular momentum

Name of unit	Symbol	Relation to SI units
Action, Angular momentum, L, J
SI unit	J·s	≡ kg·m²/s
cgs unit	erg·s	= 10^-7 J·s
atomic unit of action	au	≡ $\hbar$ = $h$ /2 $π$ ≈ 1.054 571 596×10^-34 J·s

Electric current

Name of unit	Symbol	Relation to SI units
Electric current, I
ampere	A	SI base unit
esu per second ; StatAmpere (cgs unit)	esu/s	≡ (0.1 Am/s)/c ≈ 3.335 641×10^-10 A
electromagnetic unit ; AbAmpere (cgs unit)	abamp	≡ 10 A

Electric charge

Name of unit	Symbol	Relation to SI units
Electric charge, Q
coulomb (SI unit)	C	≡ A.s
atomic unit of charge	au	≡ e ≈ 1.602 176 462×10^-19 C
StatCoulomb ; franklin; electrostatic unit (cgs unit)	statC; Fr; esu	≡ (0.1 Am)/c ≈ 3.335 641×10^-10 C
AbCoulomb (cgs unit)	AbC	≡ 10 C
Faraday	F	≡ 1 mol × N_A·e ≈ 96,485.3383 C

Electromotive force

Name of unit	Symbol	Relation to SI units
Voltage, Electromotive force, U
volt (SI unit)	V	≡ kg·m²/A·s³
AbVolt (cgs unit)	abV	≡ 1×10^-8 V
StatVolt (cgs unit)	statV	≡ c·(1 μJ/Am) = 299.792 458 V

Electrical resistance

Name of unit	Symbol	Relation to SI units
Electrical resistance, R
ohm (SI unit)	Ω	≡ V/A = kg·m²/A²s³
Dynamic viscosity, η
SI unit	Pa·s	≡ N·s/m² = kg/m·s
poise (cgs unit)	P	≡ 10^-1 Pa·s

Kinematic viscosity

Name of unit	Symbol	Relation to SI units
Kinematic viscosity, ν
SI unit	m²/s	≡ m²/s
stokes (cgs unit)	St	≡ 10^-4 m²/s

Temperature

Name of unit	Symbol	Relation to SI units
Temperature, T
kelvin	K	SI base unit
degree Celsius	°C	T[°C] = T[K] - 273.15
degree Rankine	°R; °Ra	T[°Ra] = (9/5)×T[K]
degree Fahrenheit	°F	T[°F] = T[K] × 1.8 − 459.67 (T[°F] = (9/5)×T[°C] + 32)

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