| One |
1 |
|
Unit non-dimensional quantity |
| Percent |
% |
|
Non dimensional percent (100 % == 1) |
| Parts per Million |
ppm |
|
Unitless quantity defined as 1 / 10^6 |
| Parts per Billion |
ppb |
|
Unitless quantity defined as 1 / 10^9 |
| Parts per Trillion |
ppt |
|
Unitless quantity defined as 1 / 10^12 |
| Gram |
g |
|
unit of mass defined as 1e-3 kg |
| Dalton |
Da |
u,AMU |
Sometimes called an atomic mass unit, defined as 1/12 of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest |
| Grain |
grain |
|
Mass approximately equivalent to a single ideal seed of a cereal, in particular wheat or barley |
| Ounce |
ozm |
|
US and Imperial unit equal to 1/16 of a Pound Mass |
| Dram |
dram |
|
Unit of mass historically used by apothecaries equal to 1/16 of an ounce |
| Pound |
lbm |
|
US and Imperial primary unit of mass |
| Stone |
stone |
|
Imperial unit equal to 14 Pounds Mass |
| Slug |
sg |
slug |
US and Imperial unit defined as 1 lbf / Standard Gravity |
| Short Hundredweight |
cwt |
|
Typically used in the US, equal to 100 lbm |
| Short Pennyweight |
dwt |
|
From the weight of an English penny in the Middle Ages, equal to 24 grains or 1/20 of a troy ounce |
| Long Hundredweight |
uk_cwt |
|
Typically used in the UK, equal to 8 stone |
| Ton |
ton |
|
US customary unit equal to 2000 lbm |
| UK Ton |
uk_ton |
|
English customary unit that is equal to 20 Long Hundredweight or 160 Stone |
| Metric Ton |
metric_ton |
tonne |
Sometimes seen as 'tonne', this mass equals 1000 kg |
| Carat |
carat |
|
Equal to 200 mg, typically used to measure gemstones |
| Assay Ton |
assay_ton |
|
Equal to 29 1/6 grams, often used to measure the ores of precious metals |
| Denier |
denier |
|
Linear density used in textiles, the linear density of a single strand of silk is approx. 1 denier |
| Tex |
tex |
|
Linear density equal to 1 g / km, mainly used for measuring fiber products |
| Meter |
m |
|
SI standard unit for length |
| Angstrom |
ang |
|
Equal to 10^-10 meters, often used to express the size of atoms and molecules |
| Pica Point |
picapt |
|
Used in typography, equal to 1/12 of a pica |
| Pica |
pica |
|
Used in typography, equal to 1/6 of an inch |
| Inch |
in |
|
US and Imperial unit of length equal to 1/12 of a foot |
| Mil |
mil |
|
US and Imperial units for milli-inch, avoids a unit collision with the unit 'min' |
| Foot |
ft |
|
Standard US and Imperial unit of length |
| Yard |
yd |
|
US and Imperial unit of length equal to 3 foot |
| Ell |
ell |
|
Formerly used in the english tayloring industry and defined as a yard and a quarter, now obsolete |
| Mile |
mi |
|
US and Imperial measure of distance equal to 5280 feet or 1,609.344 meters |
| Survey Mile |
survey_mi |
|
US Customary unit equal to 5280 Survey Feet |
| Nautical Mile |
nmi |
Nmi |
Approximately 1/60 of a degree of latitude, formally defined as 1852 meters |
| League |
league |
|
Originally represented the distance a person could walk in one day, the most recent common usage was in maritime where it is equal to 3 nautical miles |
| Light Year |
ly |
|
Represents the distance light travels in one year in a vacuum, used in astronomical scales |
| Parsec |
parsec |
|
Defined as 648 000 / pi astronomical units (au) |
| Survey Foot |
survey_ft |
|
Slightly different definition of foot defined as 1200/3937 meters instead of 0.3048 meters |
| Astronomical Unit |
AU |
|
Approximate distance from the Earth to the Sun |
| Chain |
chain |
|
US customary unit equal to 66 survey ft, sometimes the unit may be based on the internation foot rather than the survey foot changing the definition slightly |
| Link |
link |
|
US Customary unit of length equal to 1/100 of a chain |
| Rod |
rod |
|
US Customary unit of length equal to 1/4 of a chain |
| Furlong |
furlong |
|
US Customary unit of length equal to 10 chains |
| Fathom |
fathom |
|
Equal to 6 international foot, typically used to measure depth in maritime applications |
| US Fathom |
us_fathom |
|
US Customary Fathom, appox. equal to 6 survey foot |
| Fermi |
fermi |
|
Equal to 10^-15 m, Used in nuclear physics and named after physicist Enrico Fermi who was one of the founders of the field |
| Data Mile |
datamile |
|
A distance used in radar measurements equal to 6000 international feet |
| Kayser/Wavenumber |
kayser |
|
Reciprocal of 1 cm, used in spectroscopy and chemistry to represent the number of wavelengths per cm |
| Second |
s |
sec |
Approximately 1/86400 of a stellar day, formally defined based on the duration of 9 192 631 770 state transitions of the caesium-133 atom at 0 K |
| Minute |
min |
|
Defined as 60 seconds |
| Hour |
hr |
|
Defined as 60 minute |
| Day |
day |
|
Approximately equal to the amount of time for the earth to rotate on it's axis, formally defined as 24 hours |
| Week |
week |
|
Defined as 7 days |
| Fortnight |
fortnight |
|
Amount of time defined as 2 weeks or 14 days |
| Year |
yr |
|
Approximately equal to the amount of time for the earth to make one orbit around the sun, formally defined as 365 days |
| Shake |
shake |
|
Informal metric unit equal to 10^-8 seconds, often used in nuclear physics |
| Kelvin |
K |
deltaC |
SI standard unit with 0 defined as absolute zero |
| Degrees Fahrenheit |
degF |
|
Temperature scale that is approximately 32 at the melting point of ice and 212 at the boiling point of water |
| Degrees Celsius |
degC |
|
Temperature unit with a similar scale to Kelvin, but with the 0 approximately defined as the melting point of ice |
| Rankine |
Ra |
Rank,deltaF |
Units with the same scale as Fahrenheit, but with 0 at absolute 0 |
| Reaumur |
Reau |
|
Temperature scale that is approximately 0 at the melting point of ice and 80 at the boiling point of water |
| Delta Reaumur |
deltaReau |
|
Change in temperature as measured in Reaumurs |
| Kilometer per Hour |
kph |
|
Velocity at which a kilometer is traveled every hour |
| Mile per Hour |
mph |
|
Velocity at which a mile is traveled every hour |
| Feet per Second |
fps |
|
Velocity where 1 foot is traveled every second |
| Knot |
knot |
|
Velocity at which a Nautical mile is traveled every hour |
| Admirality Knot |
admkn |
|
Knot based on the old UK definition of a Nautical mile (1853.184 m) |
| Speed of Light |
c |
|
velocity defined by how fast light travels in a vacuum |
| Standard Gravity |
grav |
|
Approximate acceleration of gravity at the surface of the earth |
| Galileo |
galileo |
|
CGS system standard unit for acceleration |
| Pascal |
Pa |
|
SI standard unit for pressure defined as 1 N/m^2 |
| Meter of Mercury |
mHg |
|
The pressure applied by 1 m of mercury at 1 standard gravity, more commonly used as mmHg or cmHg |
| Meter of Water |
mH2O |
|
The pressure applied by 1 m of water at 1 standard gravity, more commonly used as mmH2O or cmH2O |
| Torr |
Torr |
|
Slightly different definition of mmHg, but very close to the same scale |
| Pound per Square Inch |
psi |
|
US and Imperial unit of pressure defined as 1 lbf / in^2 |
| Atmosphere |
atm |
|
Approximately the mean air pressure at sea level |
| Bar |
bar |
|
Defined as 100 000 Pa, which is very close to 1 atmosphere |
| Inch of Mercury |
inHg |
|
The pressure applied by 1 inch of mercury at 1 standard gravity |
| Inch of Water |
inH2O |
|
The pressure applied by 1 inch of water at 1 standard gravity |
| Foot of Mercury |
ftHg |
|
The pressure applied by 1 foot of mercury at 1 standard gravity |
| Foot of Water |
ftH2O |
|
The pressure applied by 1 foot of water at 1 standard gravity |
| Barye |
Ba |
|
CGS standard unit for pressure |
| Gauge Pascal |
Pa-g |
|
Pascal with a zero offset at atmospheric pressure |
| Gauge Bar |
bar-g |
|
Bar with a zero offset at atmospheric pressure |
| Gauge PSI |
psi-g |
|
psi with a zero offset at atmospheric pressure |
| Newton |
N |
|
SI standard unit for force defined as 1 kg m / s^2 |
| Dyne |
dyn |
|
CGS standard unit for force defined as 1 g [c]m / s^2 |
| Gram Force |
gf |
pond |
Defined as the amount of force exerted by standard gravity on a 1 gram mass |
| Pound Force |
lbf |
|
Defined as the amount of force exerted by standard gravity on a 1 lbm mass |
| Ounce Force |
ozf |
|
Equal to 1/16 lbf |
| Poundal |
pdl |
|
Force unit in the foot-pound-second system equal to 1 lbm ft / s^2 |
| Ton Force |
ton-force |
|
Equal to 2000 lbf |
| Joule |
J |
|
SI standard unit for energy defined as 1 N m |
| Electron Volt |
eV |
|
Energy gain of an electron after passing through a 1 Volt potential |
| Erg |
erg |
|
CGS standard unit of energy defined as 1 dyn cm |
| Calorie |
cal |
|
Based on the amount of energy needed to raise the temperature of 1 kg of water 1 degree Celsius, defined in The Fifth International Conference on the Properties of Steam (London, July 1956) 'International Table' |
| Kilo-calorie |
Cal |
|
Commonly used to measure the energy in food in the US, equal to 1000 calories and often refered to as a 'calorie' rather than a kilo-calorie |
| British Thermal Unit |
BTU |
|
Based on the amount of energy needed to raise the temperature of 1 lbm of water 1 degree Fahrenheit, defined in The Fifth International Conference on the Properties of Steam (London, July 1956) 'International Table' |
| Therm |
thm |
|
Unit of energy equal to 100 000 BTU, approximately the energy equivalent of burning 100 ft^3 of natural gas |
| Watt-hour |
Wh |
|
Amount of energy dissipated by 1 Watt source over an hour |
| Horse Power Hour |
HPh |
|
Amount of energy dissipated by a 1 HP source over an hour |
| Foot Pound-force |
ft-lb |
ft-lbf |
Defined as 1 ft x 1 lbf, typically used to describe torques rather than energy |
| R Value (SI) |
RSI |
|
Thermal insulation defined as 1 K m^2 / W |
| R Value (Foot Pound) |
RIP |
|
Thermal insulation defined as 1 Ra ft^2 hr / BTU |
| Clothing |
clo |
|
Thermal insulation unit used in clothing design, defined as the amount of insulation that allows a person at rest to maintain thermal equilibrium in an 21 degC, normally ventilated room |
| Tog |
tog |
|
Thermal insulation unit defined as exactly 0.1 K m^2 / W |
| Watt |
W |
|
SI standard unit for energy, defined as 1 J / s |
| Metric Horsepower |
PS |
|
Defined as the amount of power to raise a mass of 75 kg against standard gravity over a distance of 1 meter in one second |
| Mechanical Horsepower |
HP |
|
Defined as 33 000 ft lbf / min |
| Poise |
P |
|
CGS unit for dynamic viscosity |
| Rhe |
rhe |
|
CGS unit for fluidity, equal to exactly 1 P^-1 |
| Stokes |
St |
|
CGS unit for kinematic viscosity |
| Liter |
L |
|
Volume defined as 1 [d]m^3 or 10^-3 m^3 |
| Teaspoon |
tsp |
|
US Customary volume unit that is close to 5 mL |
| Metric Teaspoon |
tspm |
|
Based on the US Teaspoon, but defined as exactly 5 mL |
| Tablespoon |
tbs |
|
US Customary volume unit that is defined as 3 tsp |
| Fluid Ounce |
fl_oz |
|
US Customary volume unit that is defined as 2 tbs |
| UK Fluid Ounce |
uk_fl_oz |
|
Imperial unit approximately equal to the volume of 1 avoirdupois ounce of water |
| Cup |
cup |
|
US Customary volume unit that is defined as 8 fluid ounces |
| Pint |
pt |
|
US Customary volume unit that is defined as 2 cups |
| UK Pint |
uk_pt |
|
Imperial volume unit defined as 20 imperial ounces |
| Quart |
qt |
|
US Customary volume unit that is defined as 2 pints |
| UK Quart |
uk_qt |
|
Imperial volume unit defined as 2 UK pints |
| Gallon |
gal |
|
US Customary volume unit that is defined as 4 quarts |
| UK Gallon |
uk_gal |
|
Imperial volume unit defined as 4 UK quarts |
| Bushel |
bushel |
|
Very old unit of volume that is associated with agricultural production, about 2150.42 in^3 |
| Oil Barrel |
bbl |
oilbarrel |
Defined internationally as 42 US Gallons, typically used in the oil industry |
| US Beer Barrel |
beerbarrel |
|
Volume associated with beer trade in the US, equal to 31 US Gallons |
| Imperial Beer Barrel |
uk_beerbarrel |
|
Appoximate volume of a barrel used for transporting beer in the UK, equal to 36 imperial gallons |
| Measurement Ton |
MTON |
|
Commonly used in the freight industry, equal to 40 ft^3 |
| Gross Register Tonnage |
GRT |
|
commonly used in the freight industry equal to 100 ft^3 |
| Gill |
gill |
|
US Customary unit of volume equal to 4 US fluid ounces |
| UK Gill |
uk_gill |
|
Imperial unit equal to 5 Imperial (UK) fluid ounces |
| Peck |
peck |
|
US Customary unit for non-fluid volume, defined as 2 dry gallons |
| Dry Gallon |
dry_gal |
|
US Customary unit for non-fluid volume, defined as exactly 268.8025 cubic inches |
| Dry Quart |
dry_qt |
|
US Customary unit for non-fluid volume, defined as 1/4 of a dry gallon |
| Dry Pint |
dry_pt |
|
US Customary unit for non-fluid volume, defined as 1/8 of a dry gallon |
| Stere |
stere |
|
Equal to exactly 1 m^3, typically used to measure large quantities of firewood |
| Are |
ar |
|
Equal to 1/100 hectares or 100 m^2 |
| Morgen |
morgen |
|
Traditionally the area able to be plowed in a single day by a single bladed plow and an ox or horse, it now is approximately equal to 1/4 of a hectare |
| Acre |
acre |
us_acre |
Traditionally defined as the amount of area that could be plowed in one day by a yoke of oxen, still in use in the US |
| UK Acre |
uk_acre |
|
Slightly different than the US Acre, used in the UK until 1995 |
| Hectare |
ha |
|
Internationally used metric unit for measurement of the area of land, equal to 1000 m^3 |
| Barn |
barn |
|
Equal to 10^-28 m^2, originally used in nuclear physics for expressing the cross sectional area of nuclei and nuclear reactions |
| Bit |
b |
bit |
Basic unit of information that can take one of 2 states (on/off, 0/1, high/low) |
| Byte |
B |
byte |
Equal to 8 bits of information, commonly used in modern computing architectures |
| Word |
word |
|
Equal to 16 bits or 2 bytes |
| Double Word |
dword |
|
Equal to 32 bits, 4 bytes or 2 words |
| Baud Rate |
baud |
|
Rate of data transmission equal to 1 bit / second |
| Ampere |
A |
|
SI standard unit for electric current, equal to 1 C/s |
| Coulomb |
C |
|
SI standard unit for electric charge defined as the amount of charge of exactly 6.2415093e18 elementary charges |
| Amp Hour |
Ah |
|
Charge collected from 1 Amp over 1 hour |
| Elementary Charge |
e |
|
The electric charge carried by a single proton |
| Volt |
V |
|
Derived SI unit for electric potential, can be defined as J/C |
| Ohm |
ohm |
|
Derived SI unit for electrical resistance |
| Farad |
F |
|
Derived SI unit of electrical capacitance |
| Henry |
H |
|
Derived SI unit for inductance |
| Siemens |
S |
mho |
Derived SI unit for electrical conductance, equal to 1 / ohm |
| Weber |
Wb |
|
SI unit for magnetic flux defined as 1 kg m^2 / (s^2 A) |
| Maxwell |
Mx |
|
CGS unit for magnetic flux defined as 1 g cm^2 / (s^2 A) |
| Tesla |
T |
|
SI unit for magnetic flux density defined as 1 Wb / m^2 |
| Gauss |
Gs |
gs |
CGS unit for magnetic flux density defined as 1 Mx / cm^2 |
| Franklin |
Fr |
|
Standard unit of electrical charge in the EMU-CGS units of measure |
| Gilbert |
Gi |
|
Obsolete unit used in EMU-CGS systems to measure magnetization, dimensionally equivalent to the Amp |
| Oersted |
Oe |
|
CGS unit of auxiliary magnetic field |
| Mole |
mol |
|
SI standard unit for an amount of substance, defined as exactly 6.02214076e23 elementary entities (usually molecules) |
| Molar Concentration |
molar |
M |
Amount of substance per Liter of solution |
| Katal |
kat |
|
Unit of catalytic activity, defined as 1 mol / sec |
| Enzyme |
U |
|
Unit of catalytic activity, defined as 1 [u]mol / min |
| Candela |
cd |
|
SI standard unit for luminous intensity in a given direction defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540e12 Hz |
| Lumen |
lm |
|
SI derived unit of luminous flux, a measure of the total quantity of visible light emitted by a source. 1 lm = 1 cd sr |
| Lux |
lx |
|
SI derived unit of illuminance, measuring luminous flux per unit area. 1 lx = 1 lm/m^2) |
| Footcandle |
footcandle |
|
|
| Footlambert |
footlambert |
|
Non-SI unit of illuminance or light intensity. 1 footcandle = 1 lm / ft^2 |
| Lambert |
lambert |
|
Non-SI unit of luminance. 1 lambert = 1/π cd / cm^2 |
| Phot |
phot |
|
CGS unit of illuminance |
| Stilb |
stilb |
|
CGS unit of luminance |
| Radian |
rad |
|
Defined as the ratio of the radius of a circular arc to the radius of the arc, typically used to describe angles |
| Steradians |
sr |
|
A 'square radian' is a unit of solid angle analogous to the radian, a solid angle of 1 sr projected onto a unit sphere will have unit area |
| Revolution |
rev |
|
Angle describing one full revolution around an axis |
| Degree |
deg |
|
Angle measurement equal to 1/360 of a revolution |
| Arc Minute |
arcmin |
|
Angle measurement defined as 1/60 of a degree |
| Arc Second |
arcsec |
|
Angle measurement defined as 1/60 of a arc minue |
| Revolutions per Minute |
rpm |
|
Rotational frequency describing the number of revolution around an axis in a minute |
| Hertz |
Hz |
|
Frequency defined as 1 (cycle or rotation) / sec |
| Becquerel |
Bq |
|
SI derived unit for radiation activity |
| Gray |
Gy |
|
SI derived unit for radiation absorbed dose |
| Sievert |
Sv |
|
SI unit for radiation equivalent dose, although dimensionally equivalent to Gy, it also includes a weighting function for types of radiation effects on human cells, and is thus not exactly equal |
| Rontgen |
R |
|
Conventional unit for radiation exposure |
| Radiation Absorbed Dose |
RAD |
|
Conventional unit for radiation absorbed dose |
| Roentgen Equivalent Man |
rem |
|
Conventional unit for radiation equivalent dose |
| Curie |
Ci |
|
Conventional unit for radiation activity |