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# Conversion of units

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

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

 Contents

## 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
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) ≡ 1 m × 1 m
barn b ≡ 10-28
circular mil; circular thou circ mil ≡ π/4 mil² ≈ 5.067 075×10-10
square mil; square thou sq mil ≡ 1 mil² = 6.4516×10-10
circular inch circ in ≡ π/4 in² ≈ 5.067 075×10-4
square inch sq in ≡ 1 in² = 6.4516×10-4
board bd ≡ 1 in × 1 ft = 7.741 92×10-3
square link sq lnk ≡ 1 lnk² = 4.046 856 422 4×10-2
square foot sq ft ≡ 1 ft² = 9.290 304×10-2
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 BTUIT/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
hide   ≡ 100 ac = 4.046 856 422 4×105
square kilometre km² ≡ 1 km² = 106
square mile; section sq mi ≡ 1 mi² = 2.589 988 110 336×106
square statute mile; square U.S. Survey mile sq mi ≡ 1 mi (US)² ≈ 2.589 998×106
township   ≡ 36 sq mi (US) ≈ 9.323 994×107
barony   ≡ 4000 ac = 1.618 742 568 96×107

## Volume

Name of unit Symbol Relation to SI units
Volume, V
cubic metre (SI unit) ≡ 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
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
sign   ≡ 30° ≈ 0.523 599 rad
octant   ≡ 45° ≈ 0.785 398 rad
sextant   ≡ 60° ≈ 1.047 198 rad

## Mass

Name of unit Symbol Relation to SI units
Mass, m
kilogram kg (SI base unit)
electron rest mass me ≈ 9.109 381 88×10-31 ± 72×10-39 kg
atomic unit of mass au ≡ me ≈ 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
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 ≡ me·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
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 Eh ≡ me·α²·c² ≈ 4.359 744×10-18 J (= 2Ry)
atomic unit of energy au ≡ Eh ≈ 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) cal20°C ≈ 4.1819 J
calorie (thermochemical) calth ≡ 4.184 J
calorie (15°C) cal15°C ≡ 4.1855 J
calorie (International Table) calIT ≡ 4.1868 J
calorie (mean) calmean ≈ 4.190 02 J
calorie (4°C) cal4°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) BTUth ≡ 1 lb/g × 1 calth × 1 °F/°C = 9.489 152 380 4 ÷ 9 kJ ≈ 1.054 350 kJ
British thermal unit (ISO) BTUISO ≡ 1.0545 kJ
British thermal unit (63°F) BTU63°F ≈ 1.0546 kJ
British thermal unit (60°F) BTU60°F ≈ 1.054 68 kJ
British thermal unit (59°F) BTU59°F ≡ 1.054 804 kJ
British thermal unit (International Table) BTUIT ≡ 1 lb/g × 1 calIT × 1 °F/°C = 1.055 055 852 62 kJ
British thermal unit (mean) BTUmean ≈ 1.055 87 kJ
British thermal unit (39°F) BTU39°F ≈ 1.059 67 kJ
Celsius heat unit (International Table) CHUIT ≡ 1 BTUIT × 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 calIT = 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 BTUIT = 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 McalIT = 4.1868 MJ
therm (U.S.)   ≡ 100 000 BTU59°F = 105.4804 MJ
therm (E.C.)   ≡ 100 000 BTUIT = 105.505 585 262 MJ
ton of TNT tTNT ≡ 1 Gcalth = 4.184 GJ
barrel of oil equivalent bboe ≈ 5.8 MBTU59°F ≈ 6.12 GJ
ton of coal equivalent TCE ≡ 7 Gcalth = 29.3076 GJ
ton of oil equivalent TOE ≡ 10 Gcalth = 41.868 GJ
quad   ≡ 1015 BTUIT = 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 BTUIT/h ≡ 1 BTUIT/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 calIT/s ≡ 1 calIT/s = 4.1868 W
BTU (International Table) per minute BTUIT/min ≡ 1 BTUIT/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 BTUIT/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 BTUIT/s ≡ 1 BTUIT/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 BTUIT × 1 sh tn/lb ÷ 10 min/s ≈ 3.516 853×10+3 W
ton of refrigeration (Imperial)   ≡ 1 BTUIT × 1 lng tn/lb ÷ 10 min/s ≈ 3.938 875×10+3 W
boiler horsepower bhp ≈ 34.5 lb/h × 970.3 BTUIT/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/2π ≈ 1.054 571 596×10-34 J·s

## Electric current

Name of unit Symbol Relation to SI units
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
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 × NA·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
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
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)