| A |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| ab - (abbreviation
of absolute) prefix mainly attached to electric units) |
Prefix (cgs-unit) |
|
|
| abampere |
Electric current |
|
10 A |
| abcoulomb |
Electromagnetic(EM) unit of charge |
|
10 C |
| abfarad |
Electric capacitance |
|
1 x 109F |
| abhenry |
EM cgs unit of electric inductance |
|
1 x 109H |
| abohm |
EM cgs unit of conductance |
|
1 x 109W-1
1 x 109 S |
| abohm |
Electric resistance |
|
1 x 109W |
| abvolt |
EM cgs unit of electric potential |
|
1 x 10-8V |
| abvolt per cm |
EM cgs unit of electric field strength |
|
1 x 10-6V.m-1 |
| acre |
Land surface area |
|
4 046,86 m2 |
| admiralty mile (UK) |
Length; Distance (navigation) |
|
1 853 m |
| ampere |
Electric current |
A |
1 A |
| ampere (international of 1948) |
Electric current |
A |
0,999 835 A |
| ampere hour |
Power rate |
Ah |
3,6 x 103C |
| ampere metre squared |
EM moment; Magnetic dipole moment |
A.m2 |
1 A.m2
Wb.m |
| ampere per kilogram |
Exposure rate (ionising radiation) |
A.kg-1 |
1 A.kg-1 |
| ampere per metre |
Magnetic field strength |
A.m-1 |
1 A.m-1 |
| ampere per square centimetre |
Electric current density |
A.cm-2 |
1 x 104 A.m-2 |
| ampère per square metre |
Electric current density |
A.m2 |
1 A.m2 |
| ångström |
Length; Wavelength |
Å |
1 x 10-10 m |
| apothecaries ounce |
mass |
|
31,103 48 g |
| astronomical unit |
Length; Distance (astronomy) |
au |
149,598 x 109m |
| atmosphere |
Length; Distance (astronomy) |
au |
149,598 x 109m |
| atmosphere (standard) |
Pressure |
atm |
101 325 Pa |
| atomic mass unit |
Mass or Energy equivalent of Mass (1/12 of the mass of an atom of 12C |
amu (u) |
1,66 x 10-27kg
1,660 540x10-27 kg
931,49 Mev |
| atto- |
Prefix |
a |
10-18 |
| B |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| bar |
Pressure |
bar |
1 x 105(Pa) |
| barn |
Area: Particle interaction cross section |
b |
1 x 10-28m2 |
| barrel |
Volume |
bbl |
158,99 l |
| becquerel |
Radioactivity: Activity of radioactive source |
Bq |
1 s-1 |
| bel |
Sound pressure level |
B |
|
| biot |
Electric current |
biot |
10 A |
| british thermal unit |
Heat quantity;
Energy |
Btu |
1,055 kJ |
bushel (UK)
bushel (USA) |
Volume |
bu |
3,636 9 x 10m-2m3
3,524 x 10-2 m3 |
| C |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| calorie (calory) |
Heat quantity |
cal |
4,187 J
(International Table) |
| candela |
Luminous intensity |
cd |
1 cd
1 lm.sr-1
1,471 m W.sr-1 |
| candela per square metre (nit) |
Luminance |
cd.m-2
(nt) |
1 cd.m-2
1,471 mW.s-1.m-2 |
| candle |
Luminous intensity |
cd |
1,471 mW.sr-1 |
| cape foot |
Length |
|
0,314 86 m |
| cape rood |
Length |
|
3,778 m |
| carat (metric) |
Mass |
ct |
200 mg
2 x 10-4 kg |
| celsius (centigrade) |
Temperature |
°C |
t (°C)=
t(K) - 273,15 |
| centi- |
Prefix |
c |
10-2 |
| centimetre |
Length;
Distance;
Wavelength;
Displacement |
cm |
1 x 10-2 |
centimetre
of mercury
(0°C) |
Pressure |
cm Hg |
1,333 224 kPa |
centimetre of water
(4°C) |
Pressure |
cP |
98,063 Pa |
| centipoise |
Viscosity |
cP |
1 mPa.s |
| centistokes |
Kinematic viscosity |
cSt |
1 x 10-6m-2.s-1 |
| chain (eng or Ramden’s) |
Length; Distance |
|
30,48 m |
| chain (surveying or Gunter’s) |
Length, Distance |
|
20,116 8m |
| circular mil |
unit of area
(cross-section of round conductors) |
cir mil |
506,707 5 µm2 |
| clo |
amount of insulation
(skin temperature) |
|
0,200 371 K.m2, W-1 |
| coulomb |
Electric charge;
Quantity of electricity;
Flux of displacement |
C |
1 C
1 A.s |
| coulomb metre |
Electric dipole moment |
C.m |
1 C.m
1 m.s.A |
| coulomb per cubic centimetre |
Electric volume charge density |
C.cm-3 |
1 x 106 C.m-3 |
| coulomb per cubic metre |
Electric volume charge density |
C.m-3 |
1 C.m-3 |
| coulomb per square centimetre |
Electric surface charge density |
C.cm-2 |
1 x 104 C.m-2 |
| coulomb per square metre |
Dielectric polarization Displacement |
C.m-2 |
1 m-2.s.A |
| cubic centimetre |
Volume |
cm3 |
1 x 10-6m3 |
| cubic foot |
Volume |
ft3 |
2,831 7 x 10-2m3 |
| cubic metre |
Volume |
m3 |
1 m3 |
| cubic millimetre |
Volume |
mm3 |
1 x 10-9m3 |
| cubic metre per kilomole |
Inverse of particle density; Molar volume |
m3.kmol-1 |
1 x 10-3 m3.mol-1 |
| cubic metre per mole |
Inverse of particle density; Molar volume |
m3.mol-1 |
1 m3.mol-1 |
| cubic yard |
Volume |
yd3 |
0,764 555 m3 |
| cup (UK) |
Volume |
|
284,131 ml |
| cup (USA) |
Volume |
|
236,588 ml |
| curie |
Radioactivity, Activity of radioactive source |
Ci |
37 ns-1
(37 x 1010 s-1) |
| cusec (cubic foot per second) |
Flow rate |
|
(0,028 317m3 s-1) |
| cycle per second |
Frequency |
s-1 |
1 Hz |
| D |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| day (mean solar) |
Time |
d |
86,4 x 103
s |
| day (sidereal) |
|
|
86,164 x 103s |
| deca- |
Prefix |
da |
10 |
| decanewton |
Force |
daN |
10 N |
| deci- |
Prefix |
d |
10-1 |
| decibel |
Sound pressure
level |
dB |
|
| decimetre |
Length |
dm |
1 x 10-1
m |
| degree (angle) |
Angle |
...° ??? |
17,453 mrad
p 180 rad |
degree celsius
(degree centigrade) |
Temperature |
°C |
t(°C)=T(K)
- 273,15 |
| degree Fahrenheit |
Temperature |
°F |
0,5556 K
T(K)
=t(°F) + 459,67
-------------------
1,8 |
| degree Fahrenheit |
Temperature
interval |
°F |
0,555 556 (1/1,8)
K |
| degree Rankine |
Temperature
and temperature interval |
|
T(K) = t/1,8 |
| degree Rèaumur |
Temperature |
°R |
|
| drachm (fl) |
Volume |
|
3,552 x 10-3
1 |
| drachm (apothecaries) |
Mass |
|
3,887 93 g |
| dram (av) |
Mass |
|
1,771 8 g |
| dioptre (inverse
of the focal length in metre of a lens) |
Refractive
power of a lens |
d |
1 m-1 |
| debye |
Electrical
dipole moment |
D (b) |
3,335 64 x
10-30 C.m
10-18 esu |
| dyne |
Force (cgs system) |
dyn |
10 µN
cm.g.s-2 |
| E |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| e |
A constant
(base of the natural system of logarithms) |
e |
2,718 281 8 |
| ell (obsolete) |
Length |
|
0,685 8 m |
| electronvolt |
Energy |
eV |
1,602 177 x
10-19 J
1 e.C-1.J |
| electromotive force (EMF) |
Rate of energy dissipation per unit current of a source |
EMF |
1 W.A-1
m2.kg.s-3.A-1 |
| erg |
Energy; Radiant energy |
erg |
1 cm2.g.s-2
100 nJ
1 x 10-7 J |
| F |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
fahrenheit
(temperature scale) |
Temperature
unit |
°F |
t(°C)=t(°F)
- 32/1,8 |
fahrenheit
(temperature interval) |
|
°F |
t(°C) =
0,555 556 °F |
| farad |
Electric capacitance |
F |
1 m-2.kg-1.s4.A2
1 A.s. V-1
1 C.V-1 |
| farad (International
of 1948) |
Electric capacitance |
F |
0,999 505 F |
| faraday (based
on carbon-12) |
Charge to deposit
one mole of
matter electrolytically |
F |
96.487 kC.mol-1 |
| fathom |
Length (British
- usually for
water depth |
fath |
1,828 8 m |
| femto- |
Prefix |
f |
10-15 |
| femtometre |
Length |
fm |
1 x 10-15
m |
| fermi |
Length |
fm |
1 x 10-15
m |
fluid ounce
(UK)
fluid ounce (USA) |
Volume |
fl oz |
28,413 ml
29,573 ml |
| foot |
Length (British) |
ft |
0,304 8 m |
| foot (Cape) |
Length |
ft |
0,314 858 m |
foot-candella
foot-candle |
Illuminance
(British unit) |
ft cd |
10 764 1x |
| foot-lambert |
Luminance |
|
3,426 258 cd.m-2 |
| foot poundal |
Energy |
|
42,14 mJ
42,140 x 10-3 J |
| foot pound |
Torque
Energy; Work (British unit) |
ft-lb |
42,14 mN.m
1,355 8 J |
| foot pound-force |
Torque |
|
1,355 818 N.m |
| franklin |
Electric charge;
Electrostatic unit of charge |
Fr |
3,335 6 x 10-10
C |
| frigorie |
Unit of rate
of extraction of heat
Refrigeration |
|
1,162 639 W |
| furlong |
Length |
fur |
201,168 m |
| G |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| gal |
Acceleration
of free fall; Gravitational acceleration (cgs system) |
Gal |
1 x 10-2
m.s-2 |
| gallon (UK) |
Volume |
gal |
4,546 1 |
| gallon (USA) |
Volume |
gal |
3,785 l |
| gamma |
Mass |
d |
|
| gamma |
Magnetic flux
Magnetic inductance |
d |
1 x 10-9
T |
| giga- |
Prefix |
G |
109 |
| gigahertz |
Frequency |
Ghz |
1 x 109
Hz |
| giganewton per square metre |
Pressure |
GN.m-2 |
1 x 109Pa |
| gigaohm |
Electric resistance;
Impedance |
GW |
1 x 109W
.m |
| gigaohm metre |
Electric resistivity |
GW
.m |
1 x 109W
.m |
| gigawatt |
Power |
GW |
1 x 109
W |
| gigawatt hour |
Energy |
GW.h |
3,6 TJ |
| gilbert |
Magnetomotive
force
(cgs system) |
Gi(Gb) |
1 x 10-6
Tm.µ ???-1
¼ pabamp |
gill (UK)
gill (USA) |
Volume |
gill (VK)
gill (VSA) |
1,420 653 x
10-4 m3
1,182 941 x 10-4 m3 |
| gon |
Plane angle |
gon |
p
/200 rad
15,708 mrad |
| grad (grade) |
Unit of angle |
grad |
1 grad = 1
gon
= p
/200 rad |
| grain |
Mass (UK) |
gr (?) |
64,799 mg |
| gram |
Mass |
g |
1 x 10-3
kg |
| gram per cubic
centimetre |
Density |
g.cm-3 |
1 x 10-3
kg.cm-3
1 x 103 kg.cm3 |
| gram per litre |
Density |
g.l-1 |
1 x 10-3
kg.l-1 |
| gram per millilitre |
Density |
g.ml-1 |
1 x 103
kg.l-1 |
| gram per mole |
Molecular mass |
g.mol-1 |
1 x 10-3
kg.mol-1 |
| gram-rad (obsolete) |
Absorbed radiation
energy
(obsolete) |
g.rad |
10 µJ |
gram-roentgen
(gram-röntgen) |
Ionisation
charge caused by radiation (obsolete) |
g-röntgen |
258 nC |
| gray |
Absorbed radiation
dose
(derived SI unit) |
Gy |
1 J.kg-1
1 m-2.s-2 |
| H |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| hand (approx 4 inch) |
height |
|
0,1 m |
| hectare |
Surface area |
ha |
1 x 104
m2 |
| hecto- |
Prefix |
h |
102 |
| hectobar |
Pressure |
hbar |
10 x 109
Pa |
| henry |
Electric inductance
Permeance |
H |
1 m2.kg.s-2.A-2
1 V.s.A-1
1 Wb.A-1 |
| henry (International
of 1948) |
Electric inductance |
H |
1,000 495 H |
| henry per metre |
Permeability;
Inductance per unit length |
H.m-1 |
1 H.m-1
1 Wb.A-1.m-1 |
| hertz |
Frequency (cycles
per second) |
Hz |
1 s-1 |
| horsepower
(boiler) |
Power |
HP |
9,809 50 kW |
| horsepower
(UK) |
Power |
HP |
746 W |
| hour |
Time |
h |
3 600 s |
| hour (sideral) |
Time |
h |
3,590 ks |
| hubble Constant |
Expansion of
Universe |
H |
50-100 km.s-1.MPc-1 |
| hundredweight
(short) |
Mass |
cwt |
45,359 kg |
| hundredweight
(long) |
Mass |
cwt |
50,802 kg |
| I |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| inch (iron
shoes and boots) |
Length |
in or " |
2,54 x 10-2
m |
| J |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| joule |
Energy;
quantity of heat;
Work; Radiant energy
Acoustic energy;
Energy imparted;
Mean energy expanded per ion pair |
J |
1 kg.m2.s-2
1 N.m
1 V.A.s |
| joule per degree
Celsius |
Entropy |
J.°C-1 |
1 J K-1
m2kg.s-2.k-1 |
| joule metre squared per kilogram |
Total mass stopping power |
J.m2.kg-1 |
1 J.m2kg-1 |
| joule per cubic
metre |
Radiant energy
density;
Acoustic energy density |
J.m-3 |
m-1.kg.s-2
1 J.m-3 |
| joule per kelvin |
Entropy |
J.K-1 |
m2.kg.s-2.K-1
1 J.K-1 |
| joule per kelvin
mole |
Molar entropy;
Molar heat capacity |
J.K-1mol-1 |
1 J.K.mol
m2.kg.s-2
K-1.mol-1 |
| joule per kilogram |
Heat content;
Specific absorption;
Absorbed dose;
Kerma
Specific energy imparted;
Dose equivalent (weighted);
Equivalent dose (weighted);
Effective dose (weighted) |
J.kg-1 |
1 J.kg-1
m2.s-2 |
| joule per kilogram
per degree Celsius |
Specific heat
capacity |
J.kg-1.°C-1 |
1 J.kg-1.°C-1
m2.s-2.°C-1 |
| joule per kilogram
per second (or hour) |
Absorbed dose
rate;
Kerma rate;
Rates of all quantities in "joule per
kilogram" above |
J.kg-1.s-1
J.kg-1.h-1 |
J.kg-1.s-1
or
J.kg-1.h-1
m2.s-3 |
| joule per kilogram
kelvin |
Specific heat;
Specific entropy |
J.kg-1.K-1 |
J.kg-1.K-1
m2.s-2.K-1 |
| joule per kilomole
degree Celsius |
Molecular specific
heat |
J.kmol-1.°C-1 |
1 J.komol-1.°C-1 |
| joule per kilomole kelvin |
Molecular specific heat |
J.kmol-1
K-1 |
1 J.kmol-1.K-1 |
| joule per metre |
Linear energy transfer;
Lineal energy |
J.m-1 |
1 J.m-1 |
| joule per mole |
Molar energy |
J.mol-1 |
1 J.mol-1
m2.kg.s-2.mol-1 |
| joule per mole
degree Celsius |
Molar entropy;
Molar heat capacity |
J.mol-1.°C-1 |
1 J.mol-1
m2.kg.s-2.mol-1 |
| joule per mole
kelvin |
Molar entropy;
Molar heat capacity |
J.mol-1.K-1 |
1 J.mol-1.K-1 |
| joule per second |
Energy flux |
J.s-1 |
1 J.s-1
(watt) |
| joule per square
centimetre |
Radiant exposure |
J.cm-2 |
1 x 102
J.m-2 |
| joule per square
metre |
Radiant exposure;
Energy fluence;
Energy flux density |
J.m-2 |
1 J.m-2 |
| joule per square
metre per steradian |
Time-integrated
radiance |
J.m-2.sr-1 |
1 J.m-2.sr-1 |
| K |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| kayser |
Wave number |
|
100 m-1 |
| kelvin |
Temperature
(thermo-dynamic temperature) |
K |
1 K
T(K) =t(°C)+273,15 |
| kilo- |
Prefix |
k |
103 |
| kiloampere |
Electric current |
kA |
1 x 103
A |
| kiloampere
per metre |
Magnetic field
strength |
kA.m-1 |
1 x 103
A.m-1 |
| kiloampere
per square metre |
Electric current
density |
kA.m-2 |
1 x 103
A.m-2 |
| kilo calory
(International table) |
Heat quantity |
kcal |
4,186 8 kJ |
| kilocoulomb
per cubic metre |
Charge density;
Volume density of electric charge |
kC.m-3 |
1 x 103
C.m-3 |
| kilocycles
per second |
Frequency |
kHz |
1 x 103
Hz |
| kiloelectronvolt |
Energy |
keV |
1 keV |
| kilogram |
Mass |
kg |
1 kg |
| kilogram calorie
(large calorie) |
Heat quantity |
Cal |
4,187 x 103
J
(International Table) |
| kilogram metre
per second |
Linear momentum |
kg.m.s-1 |
1 kg.m.s-1 |
| kilogram metre
squared per second |
Angular momentum |
kg.m2.s-1 |
1 kg.m2.s-1 |
| kilogram per
cubic decimetre |
Density |
kg.dm-3 |
1 x 103
kg.m-3 |
| kilogram per
cubic metre |
Density |
kg.m-3 |
1 kg.m-3 |
| kilogram per
litre |
Density |
kg.1-1 |
1 kg.1-1 |
| kilogram per
mole |
Molecular mass;
Molar mass |
kg.mol-1 |
kg.mol-1 |
| kilogram per
second |
Mass flow rate |
kg.s-1 |
kg.s-1 |
| kilogram per
square metre |
Moment of interia |
kg.m-2 |
1 kg.m-2 |
| kilojoule |
Energy |
kJ |
1 kJ
1 x 103 J |
| kilojoule per
degree Celsius |
Entropy;
Heat capacity |
kJ. °C-1 |
1 kJ. °C-1
1 x 103 J. °C-1 |
| kilojoule per
kelvin |
Entropy; Heat
capacity |
kJ.K-1 |
1 x 103
J.K.-1 |
| kilojoule per
kilogram |
Specific energy |
kJ.kg-1 |
1 x 103
J.kg-1 |
| kilojoule per
kilogram degree Celsius |
Specific entropy;
Specific heat capacity |
kJ.kg-1
°C-1 |
1 x 103
J.kg-1.°C-1 |
| kilojoule per
kilogram kelvin |
Specific entropy;
Specific heat capacity |
kJ.kg-1
K-1 |
1 kJ.kg-1.K-1 |
| kilojoule per
square metre |
Radiant exposure |
kJ.m-2 |
1 x 103
J.m-2 |
| kilolitre |
Volume |
kl |
1 kl
1 x 10-3 m3 |
| kilometre |
Length; Distance;
Wavelength |
km |
1 x 103
m |
| kilometre per
hour |
Speed; Velocity |
km.h-1 |
1 x 103
m.h-1 |
| kilomole |
Substance quantity |
kmol |
|
| kilomole per
cubic metre |
Concentration |
kmol.m-3 |
1 x 103
mol.m-3 |
| kilomole per
kilogram |
Molality |
kmol.kg-1 |
1 x 103
mol.kg-1 |
| kilomole per
litre |
Concentration |
kmol.1-1 |
1 x 1010
mol.1-1 |
| kilonewton |
Force |
kN |
1 x 103
N |
| kilonewton
metre |
Work, Moment
of force; Torque |
kN.m |
1 x 103
N.m |
| kilonewton
per square metre |
Pressure |
kN.m-2 |
1 kN.m-2
1 kPa |
| kilo-ohm |
Electric resistance; |
kW |
1 x 103W |
| kilo-ohm metre |
Electric resistivity |
kW
.m |
1 x 103W
.m |
| kilopound |
Force |
|
9,806 7 N |
| kilosecond |
Time |
ks |
1 x 103
s |
| kilosiemens |
Electric conductance |
kS |
1 x 103
S |
| kilosiemens
per metre |
Electric conductivity |
kS.m-1 |
1 x 103
S.m-1
1 x 103 W-1.m-1 |
| kilovolt per
metre |
Electric field
strength |
kV.m-1 |
1 x 103
V.m-1 |
| kilowatt |
Power |
kW |
1 x 103
W |
| kilowatt hour |
Energy; Power
consumption |
kW.h |
3,6 MJ |
| kip (1000 poundon
free) |
Force |
|
4,448 22 kN |
knot (international)
USA
UK |
Speed |
kn |
1 853 m.h-1
0,514 77 m.s-1
0,514 77 m.s-1 |
| L |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| lambda |
Volume |
l |
1 x 10-9
m3 |
| lambert |
Luminance;
Brightness |
L |
3 183 cd.m-2 |
| langley |
Solar radiation |
J.m-2 |
41 849 K.m-2 |
| large calorie |
Heat quantity |
Cal |
4,187 x 103
J |
| leaguer |
|
|
577,353 1 |
| light year |
Length;
Distance |
ly |
9 460,55 Tm
(9,46x1012 km) |
| litre |
Volume |
l or L |
1 x 10-3
m3 |
| litre atmosphere |
Energy |
1.atm |
101,328 J |
| long hundredweight |
Mass |
long cwt |
50,802 kg |
| lumen |
Luminance
Luminous flux |
lm |
1 cd.sr
1,47 mW
1,47 x 10-3 W |
| lumen hour |
Quantity of
light |
lm.h |
3 600 lm.s
5,292 J |
| lumen per square
foot / metre |
Luminous existance;
Luminous flux density;
Luminous fluence rate |
lm.m-2 |
1 lm.m-2
1,47 x 10-3
J.s-1.m-2 |
| lumen second |
Quantity of
light |
lm.s
(talbot) |
1 lm.s
1,47 x 10-3 J |
| lumen second
per cubic metre |
Luminous density |
lm.s.m-3 |
1 lm.s.m-3
1,47 x 10-3 J.m-3 |
| lux |
Illuminance;
Illumination |
lx |
1 lm.m-2
1 m-2.cd.sr
1,47 mW.m-2
1,476 x 10-3
1 J.s-1.m-2 |
| lux second |
Light exposure |
lx.s |
1m.m-2.s
1,47 x 10-3 J.m-2 |
| M |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| mach |
Ratio of speed
relative to speed of sound |
Mach |
Mach 1 = ?
km.h-1 at NTP |
| man-sievert |
Collective
dose equivalent |
man-Sv |
1 man-sievert |
| maxwell |
Magnetic flux
(cgs system) |
Mx |
1 x 10-8
Wb |
| mega- |
Prefix |
m |
106 |
| mega-ampere
per square metre |
Electric current
density |
MA.m-2 |
1 MA.m-2
1 x 106 C.s-1.m-2 |
| megacoulomb |
Electric charge;
Quantity of electricity |
MC |
1 MC
1 x 106 C |
| megacoulomb
per cubic metre |
Electric volume
charge density |
MC.m-3 |
1 MC.m-3
1 x 106 C.m-3 |
| megacoulomb
per square metre |
Electric surface
charge density |
MC.m-2 |
1 MC.m-2 |
| mega-electronvolt |
Energy |
MeV |
1 x 106eV |
| megagram |
Mass |
Mg |
1 Mg
1 x 106 g |
| megagram per
cubic metre |
Density |
Mg.m-3 |
1 Mg.m-3
1 x 106 g.m-3 |
| megahertz |
Frequency |
Mhz |
1 Mhz
1 x 106 Hz |
| megajoule |
Energy |
MJ |
1 MJ
1 x 106 J |
| megajoule per kilogram |
Heat content |
MJ.kg-1 |
1 MJ.kg-1
1 x 106 J.kg-1 |
| meganewton |
force |
MN |
1 MN |
| meganewton
metre |
Work |
MN.m |
1 MN.m |
| meganewton
per square metre |
Pressure |
MN.m-2 |
1 MN.m-2
1 MPa |
| megaohm |
Electric resistance |
MW |
1 MW
1 x 106W |
| megaohm metre |
Electric resistivity |
MW
.m |
1 MW
.m
1 x 106 W
.m |
| megasiemens
per metre |
Electric conductivity |
MS.m-1 |
1 MS.m-1
1 x 106 S.m-1 |
| megavolt |
Electric potential;
Electric potential difference |
MV |
1 MV
1 x 106 V |
| megavolt per
metre |
Electric field
strength |
MV.m-1 |
1 MV.m-1
1 x 106 V.m-1 |
| megawatt |
Power |
MW |
1 MW
1 x 106 W |
| megawatt day |
Power consumption |
MW.d |
|
| megawatt hour |
Power consumption |
MW.h |
1 x 106
W.h |
| megawatt per
square metre |
Radiant energy
fluence |
MW.m-2 |
1 MW.m-2
1 x 106 W.m-2 |
| metre |
Length; Distance;
Wavelength |
m |
1 m |
| metre per second |
Velocity; Speed |
m.s-1 |
1 m.s-1 |
| metre per second
squared |
Acceleration |
m.s-2 |
1 m.s-2 |
| metre squared |
Surface area;
Particle interaction cross section |
m2 |
1 m2 |
| metre squared per kg |
Mass attenuation coefficient;
Mass energy transfer coefficient;
Mass energy absorption coefficient |
m2.kg-1 |
1 m2.kg-1 |
| metre squared
joule |
Air Kerma rate
constant |
m2.J.kg-1 |
1 m2.J.kg-1 |
| metre squared
gray per becquerel per second |
Air Kerma rate
constant (earlier known as T, i.e. specific gamma ray constant) |
m2.Gy.
Bq-1.s-1 |
1 m2.Gy.Bq-1.s-1 |
| metre squared
per second |
Kinematic viscosity;
Diffusion coefficient |
m2.s-1 |
1 m2.s-1 |
| metric horsepower |
Power |
ch or PS |
735,499 W |
| metric ton |
Mass |
t |
1000 kg |
| metric ton
per cubic metre |
Density |
t.m-3 |
1 x 103
kg.m-3 |
| mho |
Electric conductance |
mho |
mho |
| micro- |
Prefix |
µ |
10-6 |
| microampere |
Electric current |
µA |
1 x 10-6
A |
| microbar |
Pressure |
µbar |
1 µbar
1 x 10-6 bar |
| microfarad |
Electric capacitance |
µF |
1 µF
1 x 10-6 F |
| microfarad
per metre |
Permittivity;
Capacitance per unit length |
µF.m-1 |
1 µF.m-1
1 x 10-6 F.m-1 |
| microgram |
Mass |
µg |
1 µg
1 x 10-6 g |
| microhenry |
Electric inductance |
µH |
1 µH
1 x 10-6 H |
| microhenry per metre |
Permeability;
Inductance per unit length |
µH.m-1 |
1 µH.m-1
1 x 10-6 H.m-1 |
| micrometre |
Length;
Distance;
Wavelength |
µm |
1 µm
1 x 10-6 m |
| micron |
Length |
µm |
1 x 10-6
m |
| micronewton |
Force |
µN |
1 µN
1 x 10-6 N |
| micronewton
metre |
Work;
Moment of force;
Torque |
µN.m |
1 µN.m
1 x 10-6 N.m |
| micronewton
per square metre |
Pressure |
µN.m-2 |
1 µN.m-2
1 µPa |
| micro-ohm |
Electric resistance |
µW |
1 µW
1 x 10-6 W |
| micro-ohm metre |
Electric resistivity |
µW
.m |
1 µW
.m
1 x 10-6 W
.m |
| microradian |
Angle (plane
angle) |
µrad |
|
| microsecond |
Time |
µs |
1 µs
1 x 10-6 S |
| microvolt |
Electric potential |
µV |
1 µV |
| microvolt per
metre |
Electric field
strength |
µV.m-1 |
1 µV.m-1 |
| mile (also
statute mile) |
Length;
Distance |
mi or m |
1,609 3 km |
| mile per hour |
Speed |
m.h-1 |
1,609 km.h-1 |
| mil |
Thickness;
Distance |
mil |
2.54 x 10-5
m |
| mil (circular) |
|
|
506,707 µm2 |
| mil (milli-inch)
(thou) |
Thickness;
Distance |
|
25,4µm |
| milli- |
Prefix |
m |
10-3 |
| millampere |
Electric current |
mA |
1 x 10-3A |
| millibar |
Pressure |
mbar |
1 x 102
Pa |
| millifarad
per metre |
Permittivity |
mF.m-1 |
1 x 103
F.m-1 |
| millimetre
squared per second |
|
mm2.s-1 |
1 x 10-6
m2.s-1 |
| millinewton
per metre |
|
mN.m-1 |
1 x 10-3
N.m-1 |
| millinewton
second per metre |
|
mN.s.m-2 |
1 x 10-3
N.s.m-2 |
| milliohm metre |
Electric resistivity |
mW
.m |
1 x 10-3W
.m |
| milliradian |
Angle |
mrad |
1 x 10-3
rad |
| millimetre
of mercury |
Pressure |
mmHg |
133,322 Pa |
| millibar |
Pressure |
mbar |
1 x 102
Pa |
| millisecond |
Time |
ms |
1 x 10-3
s |
| millitorr |
Pressure |
mTorr |
1,333 mPa
1,333 x 10-3 Pa |
| millivolt per
metre |
Electric field
strength |
mV.m-1 |
1 x 10-3
V.m-1 |
| millivolt ampere |
Power |
mV.A |
1 x 10-3
V.A |
| milliwatt |
Power |
mW |
1 x 10-3
W |
| minute |
Volume |
...1 |
µ10/800
rad |
| minute (mean
solar) |
Time |
min |
60 s |
| minute (sidereal) |
Time |
|
59,836 17 s |
| mole |
Substance quantity;
(amount of substance);
Avogadro’s number |
mol |
1 mol |
| mole per joule |
Radiation chemical
yield |
mol.J-1 |
1 mol.J-1 |
| mole per cubic
metre |
Concentration |
mol.m-3 |
1 mol.m-3 |
| mole per kilogram |
Inverse of molar mass;
molality |
mol.kg-1 |
1 mol.kg-1 |
| mole per litre |
Concentration |
mol.l-1 |
1 mol.l-1 |
| month |
Time |
mo |
2,628 Ms |
| morgen |
Surface area |
|
856 5 m2 |
| muid (obsolete) |
Volume |
|
|
| mud |
Volume |
|
10,911 x 10-2
m3 |
| myria metre
(USA) |
Wavelength |
|
10-4
m |
| N |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| nano- |
Prefix |
n |
10-9 |
| nanoampere |
Electric current |
nA |
1 x 10-9
A |
| nanofarad per
metre |
Permittivity;
capacitance per unit length |
nF.m-1 |
1 x 10-9
F.m-1 |
| nanometre |
Length |
nm |
1 x 10-9
m |
| nano-ohm metre |
Resistivity |
nµ.m |
1 x 10-9
µ.m |
| nanosecond |
Time |
ns |
1 x 10-9
s |
| nanotesla |
Magnetic flux
density |
nT |
1 x 10-9
T |
| nautical mile
(UK) |
Length; Distance;
(sea and air navigation) |
nm (NM) (obsolete) |
1 853 m |
| nautrical mile
(Int) |
Length; Distance |
|
1 852 m |
| neper (napier) |
Natural logarithm;
log of square of ratio of two quantities |
Np |
|
| newton |
Force |
N |
1 kg.m.s-2 |
| newton metre |
Work;
Moment of force;
Torque |
N.m |
1 J
1 m2.kg.s-2 |
| newton metre
squared per ampere |
|
N.m2.A-1 |
1 N.m2.A-1 |
| newton per
metre |
Surface tension |
N.m-1 |
1 kg.s-2
1 N.m-1 |
| newton per square metre |
Pressure |
N.m-2 |
1 N.m-2 |
| newton second per square metre |
Dynamic viscosity |
N.s.-2 |
1 N.s.m-2 |
| nit |
Luminance |
nt |
1 cd.m-2 |
| O |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| oersted |
Magnetic intensity
(cgs system) |
Oe |
79,577 A.m-1 |
| ohm |
Electric resistance;
Electric impedance;
Wave impedance |
µ |
1 kg.m2.s-3.A-2
1 V.A-1 |
| ohm metre |
Electric resistivity |
W.m |
1 W.m
1 kg.m3.s-3.A-2 |
| ohm millimetre |
Electric resistivity |
W.mm |
1 x 10-3W
.m |
| ounce (avoirdupois) |
Mass |
oz avdp |
28,349 5 g |
| ounce (apothecaries’
or troy) |
Mass |
oz |
31,103 5 g |
| ounce (UK)
(also fluid ounce) |
Volume |
fl oz |
28,413 ml |
| ounce (USA)
(fluid ounce) |
Volume |
fl oz (liq
oz) |
29,573 ml |
| P |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| parsec |
Distance (astronomy) |
pc |
3.086 x 1016
m |
| pascal |
Pressure, Stress |
Pa |
1 kg.m-1.s-2
1 N.m-2
1 J.m-3 |
| pascal second |
Dynamic viscosity |
Pa.s |
1 kg.m-1.s-1 |
| peck (UK) |
Volume |
|
9,092 18 x
10-3.m3 |
| peck (USA) |
volume |
|
8,809 768 x
10-3.m3 |
| pennyweight |
Mass |
dwt
(also pwt) |
1,555 2 g |
| per degree
Celsius |
Inverse of
degree Celsius |
°C-1 |
1 °C-1 |
| per henry |
Inverse of inductance;
Reluctance |
H-1 |
1 H-1
1 m-2.kg-1.s2.A2 |
| per kelvin |
Inverse of temperature;
Coefficient of linear expansion |
K-1 |
1 K-1 |
| per metre |
Linear attenuation
coefficient;
Macroscopic cross section;
Linear absorption coefficient;
Linear energy absorption coefficient;
Wave number |
m-1 |
1 m-1 |
| per ohm |
Inverse of
electric resistance |
W-1 |
1 W-1 |
| per ohm metre |
Inverse of
electric resistivity |
W-1.m-1 |
1 W-1.m-1 |
| per second |
Frequency;
Radioactivity;
Particle flux;
Decay constant;
Source strength |
s-1 |
1 s-1 |
| per square
metre |
Particle fluence |
m-2 |
1 m-2 |
| per square
metre per second |
Fluence rate;
Flux density |
m-2.s-1 |
1 m-2.s-1 |
| per square
metre per second |
Fluence rate;
Flux density |
m-2.s-1 |
1 m-2.s-1 |
| per square
metre per second per steradian |
Particle radiance;
Angular fluence rate;
Angular flux density |
m-2.s-1.sr-1 |
1 m-2.s-1.sr-1 |
| perm inch (0°C) |
|
|
1,453 22 x
10-12kg.m.N-1.s-1 |
| perm (°C) |
Degree of permeability
(porous reservoir structure) |
|
5,721 4 x 10-11kg.
N-1.s-1 |
| phot |
Illuminance;
Illumination |
ph |
10 klx
1 cm-2.cd.sr
1,47 mW.m-2 |
| pi |
Constant |
p |
3,141 593 |
| pico- |
Prefix |
p |
10-12 |
| picoampere |
Electric current |
pA |
1 x 10-12
A |
| picofarad per
metre |
Capacitance
per unit length |
pF.m-1 |
1 x 10-12
F.m-1 |
| pica (printers) |
Letter type
width |
pc |
4,217 52 x
10-3 m |
| pièze |
Pressure |
pieze |
1 kPa |
| pint |
Volume |
pt |
0,568 1 |
| point (printers)
(7½ inch) |
Printers’ measure |
pt |
0,352 46 x
10-3 m |
| poise |
Viscosity |
P |
100 mPa.s
1 cm-1.g.s-1 |
| poundal |
Force (fps
system) |
|
138,26 mN |
| pound |
Mass |
lb |
453,59 24 g |
| pound-force |
Force |
lbf |
4,448 N |
| pound-force
per square inch |
Force; Pressure |
|
6,794 8 kPa |
| pound per square
inch |
Pressure |
lb.in-2
or psi |
6,895 kPa |
| Q |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| quart (UK) |
Volume |
qt |
1,136 52 l |
| quart (USA) |
Volume (dry) |
qt |
1,101 22 l |
| R |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| rad (obsolete) |
Absorbed radiation
dose;
Kerma |
rad |
10 mJ.kg-1
0,01 Gy |
| rad per hour
(obsolete) |
Absorbed dose
rate;
Kerma rate |
rad.h-1 |
|
| radian |
Angle (plane
angle) |
rad |
m.m-1
= 1 |
| radian per
second |
angular velocity |
rad.s-1 |
1 rad.s-1 |
| radian per second squared |
Angular acceleration |
rad.s-2 |
1 rad.s-2 |
| rankine (degree Rankine) |
Thermodynamic temperature |
°R |
5/9 K |
| rem (obsolete) |
Dose equivalent |
rem |
0,01 Sv |
| rem per hour |
Dose equivalent
rate (obsolete) |
rem.h- |
0,01 Sv.h-1 |
| revolutions
per minute |
Rotational
frequency |
r.min-1 |
|
| rhe |
Dynamic fluidity |
|
10 Pa-1.s-1 |
| rod (UK and
USA) |
Length |
rd |
5,029 m |
| roentgen (obsolete
also röntgen) |
Exposure to
radiation |
R |
258 µC.kg-1
2,58 x 10-4 C.kg-1 |
| roentgen per
hour (obsolete) |
Exposure rate |
R.h-1 |
0,01 Sv.h-1 |
| rood (Cape) |
Length |
|
3,778 m |
| S |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| sabin |
Acoustic absorption |
|
|
| scruple |
Mass |
|
1,295 98 x
10-3 kg |
| second |
Time |
s |
1 s |
| second (angle) |
Angle |
..." |
4,848 µrad |
| shed |
Transfer probability |
shed |
1 x 10-52
m2 |
| siemens |
Nuclear physics
Electric conductance |
S |
1 m-2.kg-1.s3.A2
1 W-1 |
| siemens per
metre |
Electric conductivity |
S.m-1 |
1 A2.s3.kg-1.m-3 |
| sievert (derived
SI unit) |
Dose equivalent;
Equivalent dose;
Effective dose |
Sv |
1 J.kg-1 |
| sievert per
hour |
Dose equivalent
rate;
Effective dose rate |
Sv.h-1 |
J.kg-1.s-1 |
| slug |
Mass |
|
14,593 9 kg |
| square centimetre |
Surface area |
cm2 |
1 x 10-4m2 |
| square kilometre |
Surface area |
km2 |
1 x 106m2 |
| square metre |
Surface area;
Particle interaction cross section |
m2 |
1 m2 |
| square metre
per kilogram |
Mass attentuation
coefficient;
Mass energy transfer coefficient |
m2.kg-1 |
1 m2.kg-1 |
| square metre
per second |
Kinematic viscosity |
m2.s-1 |
1 m2.s-1 |
| square millimetre |
Surface area |
mm2 |
1 x 10-6
m2 |
| standard atmosphere |
Pressure |
atm |
101 325 Pa |
| short hundredweight |
Mass |
cwt |
45,359 kg |
| standard acceleration
of gravity |
Acceleration |
Gn |
9,806 65 m.s-2 |
| statfarad |
Electrostatic
unit of capacity (cgs system) |
|
1,112 7 pF |
| stathenry |
Electrostatic
unit of inductance (cgs system) |
|
895,755 GH |
| statvolt |
Electrostatic
unit of potential (cgs system) |
|
299,792 V |
| statcoulomb |
Electrostatic
unit of charge |
|
3,3 x 10-10
C |
| statute mile |
Length; Distance |
mi |
1,609 3 km |
| steradian (sterad) |
Solid angle |
sr |
m2.m-2
= 1 |
| sthène |
Force (mks
unit) |
|
1 x 103
N |
| stere |
Volume |
st |
1 m3 |
| stilb |
Luminance |
sb |
1 cm-2.cd
10 kcd.m-2 |
| stokes |
Kinematic viscosity |
st |
100 mm2.s-1
1 x 10-4 m2.s-1 |
| stone |
Mass |
|
6,350 3 kg |
| T |
|
|
back to top |
| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| tablespoon (UK) |
Volume |
|
14,206 53 ml |
| tablespoon
(USA) |
Volume |
|
14,786 76 ml |
| teaspoon (UK) |
Volume |
|
4,735 51 ml |
| teaspoon (USA) |
Volume |
|
4,928 92 ml |
| talbot |
Light quantity |
|
1 lm.s |
| tera- |
Prefix |
T |
1012 |
| terahertz |
Frequency |
Thz |
1 x 1012
Hz |
| tesla |
Magnetic flux
density;
Magnetic induction;
Magnetic polarization |
T |
1 kg.s-2.A-1
1 V.s.m-2
1 Wb.m-2
1 N.A-1.m-1 |
| tex |
Yarn mass unit;
Mass per unit length |
tex |
1 mg.m-1 |
| thou (milli-inch) |
Length, Thickness |
|
25,4 µm |
| therm |
|
|
105,506 MJ |
| thermie |
|
|
4,1855 MJ |
ton (long)
(2250 pounds) |
Mass (UK) |
longton (lt?) |
1 016,06 kg |
ton (short)
(2000 pounds) |
Mass |
short ton (st?) |
907,2 kg |
| ton (metric)
tonne |
Mass |
t |
1 Mg
1 x 103 kg |
| torr |
Pressure |
Torr |
133,32 Pa |
| U |
|
|
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| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| unit pole |
Unit of magnetic
flux |
|
125,664 nWb |
| V |
|
|
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| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| volt |
Electric potential;
Voltage;
Potential difference;
Electromotive force |
V |
1 m2.kg.s-3.A-1
1 J.A-1.s-1
1 W.A.-1 |
| volt ampere |
Power |
V.A |
1 V.A |
| volt ampere reactive |
Reactive power (electrical engineering) |
var |
|
| volt per centimetre |
Electric field
strength |
V.cm-1 |
1 x 102
V.m-1 |
| volt per metre |
Electric field
strength |
V.m-1 |
1 m.kg.s-3.A-1
1 V.m-1 |
| volt second |
|
V.s |
1 V.s |
| W |
|
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| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| watt |
Power;
Radiant flux;
Radiant energy flux;
Radiant power;
Acoustic power |
W |
1 m2.kg.s-3
1 J.s-1 |
| watt hour |
Energy; Power
consumption |
W.h |
3,6 kJ |
| watt per metre
degree celsius |
Thermal conductivity |
W.m-1.
°C |
J.s-1.
°C-1 |
| watt per metre
kelvin |
thermal conductivity |
W.m-1.K-1 |
1 J.s-1.m-1.K-1 |
| watt per square
metre |
Radiant energy
fluence rate;
Radiant energy flux density;
Irradiance;
Radiant excitance;
Surface power density;
Acoustic intensity |
W.m-2 |
1 J.s-1.m-2 |
| watt per square
metre per kelvin |
Coefficient
of heat transfer |
W.m-2.K-1 |
1 kg.s-3.K-1
W.m-2.K-1 |
| watt per square
metre per steradian |
Energy radiance |
W.m-2.sr-1 |
1 J.s-1.m-2.sr-1 |
| watt second |
Energy |
W.s |
1 J |
| watt per steradian |
Radiant intensity |
W.sr-1 |
1 J.s-1.sr-1
1 kg. m2.s-3.sr-1 |
| weber |
Magnetic flux |
Wb |
1 kg. m2.s-2.A-1
1 V.s |
| weber metre |
Magnetic dipole moment |
Wb.m |
1 Wb.m |
| weber per metre |
|
Wb.m-1 |
1 Wb.m-1 |
| weber per square
metre |
Magnetic flux
density |
Wb.m-2 |
1 T |
| weber per millimetre |
|
Wb.mm-1 |
1 x 103
Wb.m-1 |
| week |
Time |
wk |
604,8 ks |
| X |
|
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| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| x-axis |
Horizontal axis on a graph. |
|
|
| x-ray radiation |
Form of electromagnetic radiation. |
|
0.03 to 30 nm |
| Y |
|
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| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| yard |
Length |
yd |
0,914 4m |
| year (calender) |
Time |
y |
31,536 Ms
(365,0 days) |
| year (sidereal) |
Time |
sid.y |
31,558 15 Ms |
| year (tropical) |
Time |
tr.y |
31,556 9 Ms |
| Z |
|
|
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| Unit / Term |
Quantity / Entity |
Symbol |
SI-Relation |
| z-value |
An index of the ionizing power |
Z |
Z = 2.859 x 104/λ |
|
Scientific Units/Terms