| Unit Name | Symbol | Aliases | Description | | ----------------------- | ------------- | -------- | ---------------------------------------------------------- | | 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 |