# Units of Measurement | IntroductoryExamples

SI Unit Symbols
A, bar, Bq, C, cd, d, dB, dbar, ° (deg), °C (degC), eV, F, g, Gy, h, H, Hz, J, K, kat, kg, l, L, lm, lx, m, mbar, min, mol, N, Ω (Ohm), Pa, phon, rad, rev, Hz/2π (revHz), rpm, s, S, sone, sr, Sv, T, V, var, W, Wb
All Unit Symbols
A, atm, bar, Bq, C, cal, cd, CGSdebye, CGSFr, CGSstatC, Ci, d, dB, dbar, debye, ° (deg), °C (degC), °F (degF), °Rk (degRk), dyn, EMUFr, EMUstatC, ESUdebye, ESUFr, ESUstatC, eV, F, floz, ft, g, gal, Gy, h, H, hpE, hpI, hpM, hpS, Hz, in, Btuⁱ (ITBtu), kBtuⁱ (ITkBtu), J, K, kat, kg, kn, l, L, lb, lbf, lm, lx, m, mbar, mi, min, mol, mph, N, nmi, Ω (Ohm), oz, ozf, Pa, % (percent), (permille), phon, ppm, psi, rad, Rd, rem, rev, Hz/2π (revHz), rpm, s, S, sone, sr, st (stone), Sv, T, Btuₜₕ (TCBtu), kBtuₜₕ (TCkBtu), UKfloz, UKgal, V, var, W, Wb, yd, yr
Unit Symbols
atm — standard atmosphere
Symbol: atm
Definition: x atm = (101325 x) Pa
Wolfram Language: "Atmospheres"
QuantitiesDisplay Units
Fugacity, Pressureatm
bar — bar
Slightly less than one standard atmosphere.
Symbol: bar
Definition: x bar = (100000 x) Pa
Wolfram Language: "Bars"
Derived units: dbar, mbar
QuantitiesDisplay Units
Fugacity, Pressurebar
PressureRatebar/s
Bq — becquerel
Symbol: Bq (prefixable)
Definition: x Bq = x 1/s
Wolfram Language: "Becquerels"
Derived units: Rd, Ci
QuantitiesDisplay Units
Activity, RateBq
SpecificActivityBq/kg
cal — thermochemical calorie
Symbol: cal (prefixable)
Definition: x cal = (4.184 x) J
Wolfram Language: "ThermochemicalCalories"
Derived units: Btuₜₕ
Unit does not appear in the display units configured for any quantity.
cd — candela
Symbol: cd (prefixable)
Base unit
Wolfram Language: "Candelas"
Derived units: lm
QuantitiesDisplay Units
Luminancecd/m2
LuminousIntensitycd
CGSdebye — debye
In other contexts, sometimes denoted with symbol D.
Symbol: CGSdebye
Definition: x CGSdebye = (1e-18 x) CGSstatC⋅cm
Wolfram Language:
"Atto" "Centimeters"^(5/2) "Grams"^(1/2) / "Seconds"
CGSFr — franklin
Alternative name for statcoulomb (CGSstatC).
Symbol: CGSFr
Definition: x CGSFr = x CGSstatC
Wolfram Language:
"Centimeters"^(3/2) "Grams"^(1/2) / "Seconds"
CGSstatC — statcoulomb
Electrostatic unit of charge. Also known as franklin (CGSFr).
Symbol: CGSstatC (prefixable)
Definition: x CGSstatC = x dyn1/2⋅cm
Wolfram Language:
"Centimeters"^(3/2) "Grams"^(1/2) / "Seconds"
Derived units: CGSFr, CGSdebye
Ci — curie
Symbol: Ci (prefixable)
Definition: x Ci = (3.7e+10 x) Bq
Wolfram Language: "Curies"
QuantitiesDisplay Units
Activity, RatepCi, Ci
d — day
Symbol: d
Definition: x d = (24 x) h
Wolfram Language: "Days"
Derived units: yr
dB — decibel
Symbol: dB
Base unit
Wolfram Language: IndependentUnit["decibels"]
dbar — decibar
Isolated prefix variant of the bar symbol. Used mainly in oceanography.
Symbol: dbar
Definition: x dbar = (0.1 x) bar
Wolfram Language: "Decibars"
Unit does not appear in the display units configured for any quantity.
debye — debye of charge
Alternative name for debye of charge (ESUdebye).
Symbol: debye
Definition: x debye = x ESUdebye
Wolfram Language: "Debyes"
° — degree
Symbol: deg
Definition: x ° = (0.0174533 x) rad
Wolfram Language: "AngularDegrees"
°C — degree Celsius
Symbol: degC
Definition: x °C = (x + 273.15) K
Default kind of quantity: Absolute
Wolfram Language: "DegreesCelsius"
QuantitiesDisplay Units
ThermodynamicTemperature°C
°F — degree Fahrenheit
Symbol: degF
Definition: x °F = (x + 459.67) °Rk
Default kind of quantity: Absolute
Wolfram Language: "DegreesFahrenheit"
QuantitiesDisplay Units
ThermodynamicTemperature°F
°Rk — degree Rankine
Symbol: degRk
Definition: x °Rk = (0.555556 x) K
Default kind of quantity: Absolute
Wolfram Language: "DegreesRankine"
Derived units: Btuₜₕ, °F, Btuⁱ
QuantitiesDisplay Units
ThermodynamicTemperature°Rk
dyn — dyne
Symbol: dyn (prefixable)
Definition: x dyn = x g⋅cm/s2
Wolfram Language: "Dynes"
Derived units: CGSstatC
QuantitiesDisplay Units
Force, ImpulseFlowRate, MomentumFluxdyn
EMUFr — franklin of flux
Flux interpretation of franklin. Alternative name for statcoulomb of flux (EMUstatC).
Symbol: EMUFr
Definition: x EMUFr = x EMUstatC
Wolfram Language:
"Statcoulombs" ("Radians" "Pints") / ("FullAngle" "Quarts")
QuantitiesDisplay Units
ElectricFluxEMUFr
EMUstatC — statcoulomb of flux
Flux interpretation of statcoulomb. Electrostatic unit of charge. Also known as franklin of charge (ESUFr).
Symbol: EMUstatC (prefixable)
Definition: x EMUstatC = (0.0795775 x) ESUstatC
Wolfram Language:
"Statcoulombs" ("Radians" "Pints") / ("FullAngle" "Quarts")
Derived units: EMUFr
QuantitiesDisplay Units
ElectricFluxEMUstatC
ESUdebye — debye of charge
Charge interpretation of debye. In the Modelica Standard Library, denoted with symbol debye. In other contexts, sometimes denoted with symbol D.
Symbol: ESUdebye
Definition: x ESUdebye = (1e-18 x) ESUstatC⋅cm
Wolfram Language: "Debyes"
Derived units: debye
ESUFr — franklin of charge
Charge interpretation of franklin. Alternative name for statcoulomb of charge (ESUstatC).
Symbol: ESUFr
Definition: x ESUFr = x ESUstatC
Wolfram Language: "Franklins"
QuantitiesDisplay Units
ElectricCharge, ElementaryChargeESUFr
ESUstatC — statcoulomb of charge
Charge interpretation of statcoulomb. Electrostatic unit of charge. Also known as franklin of flux (ESUFr).
Symbol: ESUstatC (prefixable)
Definition: x ESUstatC = (3.33564e-10 x) C
Wolfram Language: "Statcoulombs"
Derived units: ESUFr, ESUdebye, EMUstatC
QuantitiesDisplay Units
ElectricCharge, ElementaryChargeESUstatC
eV — electronvolt
Symbol: eV
Definition: x eV = (1.60218e-19 x) J
Wolfram Language: "Electronvolts"
QuantitiesDisplay Units
Energy, LevelWidth, WorkeV
Symbol: F (prefixable)
Definition: x F = x C/V
QuantitiesDisplay Units
CapacitancepF, nF, μF, mF, F
CapacitancePerAreaF/m2
PermittivityF/m
floz — US fluid ounce
Symbol: floz
Definition: x floz = (29.5735 x) mL
Wolfram Language: "FluidOunces"
Derived units: gal
Unit does not appear in the display units configured for any quantity.
g — gram
Symbol: g (prefixable)
Definition: x g = (0.001 x) kg
Wolfram Language: "Grams"
Derived units: Btuₜₕ, dyn, Btuⁱ
gal — US gallon
Symbol: gal
Definition: x gal = (128 x) floz
Wolfram Language: "Gallons"
QuantitiesDisplay Units
DerEnergyByPressure, Volumegal
Gy — gray
Symbol: Gy (prefixable)
Definition: x Gy = x J/kg
Wolfram Language: "Grays"
h — hour
Symbol: h
Definition: x h = (60 x) min
Wolfram Language: "Hours"
Derived units: d, mph, kn
H — henry
Symbol: H (prefixable)
Definition: x H = x Wb/A
Wolfram Language: "Henries"
QuantitiesDisplay Units
Inductance, PermeancepH, nH, μH, mH, H, kH
PermeabilityH/m
Reluctance1/H
hpE — electrical horsepower
Symbol: hpE
Definition: x hpE = (746 x) W
Wolfram Language: "ElectricalHorsepower"
QuantitiesDisplay Units
PowerhpE
hpI — imperial horsepower
Also denoted mechanical horsepower.
Symbol: hpI
Definition: x hpI = (745.7 x) W
Wolfram Language: "MechanicalHorsepower"
QuantitiesDisplay Units
PowerhpI
hpM — metric horsepower
Symbol: hpM
Definition: x hpM = (735.499 x) W
Wolfram Language: "MetricHorsepower"
QuantitiesDisplay Units
PowerhpM
hpS — steam horsepower
Also denoted boiler horsepower.
Symbol: hpS
Definition: x hpS = (9810.56 x) W
Wolfram Language: "BoilerHorsepower"
QuantitiesDisplay Units
PowerhpS
Hz — hertz
Symbol: Hz (prefixable)
Definition: x Hz = x 1/s
Wolfram Language: "Hertz"
Derived units: Hz/2π
QuantitiesDisplay Units
Frequency, RatekHz, MHz, GHz, THz
in — inch
Symbol: in
Definition: x in = (2.54 x) cm
Wolfram Language: "Inches"
Derived units: ft, psi
Btuⁱ — International table British thermal unit
Symbol: ITBtu
Definition: x Btuⁱ = (4.1868 x) Jlb°Rk/(gK)
Wolfram Language:
"InternationalTableBritishThermalUnits"
Derived units: kBtuⁱ
QuantitiesDisplay Units
Energy, WorkBtuⁱ
kBtuⁱ — 1000 International table British thermal unit
Symbol: ITkBtu
Definition: x kBtuⁱ = (1000 x) Btuⁱ
Wolfram Language:
"Kilo" "InternationalTableBritishThermalUnits"
QuantitiesDisplay Units
Energy, WorkkBtuⁱ
kat — katal
Symbol: kat (prefixable)
Definition: x kat = x mol/s
Wolfram Language: "Katals"
Unit does not appear in the display units configured for any quantity.
kn — knot
Symbol: kn
Definition: x kn = x nmi/h
Wolfram Language: "Knots"
QuantitiesDisplay Units
Velocitykn
l — liter
Alternative unit symbol with lower case letter.
Symbol: l (prefixable)
Definition: x l = x L
Wolfram Language: "Liters"
Unit does not appear in the display units configured for any quantity.
L — liter
Symbol: L (prefixable)
Definition: x L = x dm3
Wolfram Language: "Liters"
Derived units: floz, UKfloz, l
lb — international avoirdupois pound
Symbol: lb
Definition: x lb = (0.453592 x) kg
Wolfram Language: "Pounds"
Derived units: Btuₜₕ, oz, st, Btuⁱ
lbf — pound-force
Symbol: lbf
Definition: x lbf = (4.44822 x) N
Wolfram Language: "PoundsForce"
Derived units: psi, ozf
lm — lumen
Symbol: lm (prefixable)
Definition: x lm = x cdsr
Wolfram Language: "Lumens"
Derived units: lx
lx — lux
Symbol: lx (prefixable)
Definition: x lx = x lm/m2
Wolfram Language: "Lux"
QuantitiesDisplay Units
Illuminancemlx, lx
LightExposurelxs
m — meter
Symbol: m (prefixable)
Base unit
Wolfram Language: "Meters"
Derived units: J, L, N, ESUdebye, dyn, nmi, lx, CGSstatC, in, CGSdebye, Pa, T
QuantitiesDisplay Units
Accelerationm/s2
AcceptorNumberDensity, DonorNumberDensity, ElectronNumberDensity, HoleNumberDensity, IntrinsicNumberDensity, IonNumberDensity, MolecularConcentration, NeutronNumberDensity, NumberDensityOfMolecules1/m3
AcousticImpedancePas/m3
AngularCrossSectionm2/sr
AngularImpulseNms
AngularImpulseFlowRate, AngularMomentumFlux, TorqueN⋅cm, Nm
AngularMomentumkgm2/s
AreaPerVoltageSecondcm2/(Vs)
AttenuationCoefficient, CircularWavenumber, DebyeCircularWavenumber, FermiCircularWavenumber, LinearAbsorptionCoefficient, MacroscopicCrossSection, PhaseCoefficient, PropagationCoefficient, TotalMacroscopicCrossSection, WaveNumber1/m
CapacitancePerAreaF/m2
CoefficientOfHeatTransferW/(m2K)
Concentration, MolarDensitymol/m3
Conductivity, ElectrolyticConductivityS/m
CurrentDensityA/m2
CurrentDensityOfParticles, NeutronFluenceRate1/(m2s)
Density, MassConcentrationkg/m3, kg/dm3, g/cm3
DensityOfStates, IsothermalCompressibilityJ-1/m-3
DerEnergyByPressure, SectionModuluscm3, dm3, m3, m4/m
DerVolumeByMoles, MolarVolumem3/mol
DiffusionCoefficient, KinematicViscosity, ParticleFluenceRate, ThermalDiffusionCoefficient, ThermalDiffusivitym2/s
ElectricalTorqueConstantNm/A
ElectricDipoleMoment, ElectricDipoleMomentOfMoleculeCm
ElectricFieldStrength, ElectrizationV/m
ElectricFluxDensity, ElectricPolarization, SurfaceDensityOfChargeC/m2
ElectricPolarizabilityOfAMoleculeCm2/V
ElectromagneticMoment, MagneticMomentOfParticleAm2
EnergyDensityJ/m3
EnergyFluenceJ/m2
GyromagneticCoefficientAm2/(Js)
HallCoefficientm3/C
Jerkm/s3
Length, SLength, Wavelengthμm, mm, cm, m, km
LinearCurrentDensity, MagneticFieldStrength, MagnetizationA/m
LinearDensitykg/m
LinearEnergyTransfer, TotalLinearStoppingPowerJ/m
Luminancecd/m2
LuminousExitancelm/m2
MagneticDipoleMomentWbm
MagneticVectorPotentialWb/m
MassAttenuationCoefficient, MassEnergyTransferCoefficientm2/kg
MeanMassRange, SurfaceDensitykg/m2
MechanicalImpedance, TranslationalDampingConstantN/(m/s), kNs/m
Mobilitym2/(Vs)
MolarAbsorptionCoefficient, MolarAttenuationCoefficientm2/mol
MolarConductivitySm2/mol
MomentOfInertiakg⋅cm2, kgm2
Momentumkgm/s
ParticleFluence1/m2
PerArea1/m2, 1/cm2
PermeabilityH/m
PermittivityF/m
RecombinationCoefficient, VolumeFlowRatem3/d, m3/h, m3/min, m3/s
ResidualResistivity, ResistivityΩm
RichardsonConstantA/(m2K2)
SecondMomentOfAream4
SlowingDownDensity, TotalNeutronSourceDensity1/(sm3)
SpecificAcousticImpedancePas/m
SpecificVolumem3/kg
SpectralAngularCrossSectionm2/(srJ)
SpectralConcentrations/m3
SpectralCrossSectionm2/J
SurfaceTension, TranslationalSpringConstantN/m
ThermalConductivityW/(mK)
ThermalInsulancem2K/W
TotalAtomicStoppingPowerJm2
TotalMassStoppingPowerJm2/kg
Velocitykm/h, m/s
Volumecm3, dm3, m3
VolumeDensityOfChargeC/m3
mbar — millibar
Isolated prefix variant of the bar symbol.
Symbol: mbar
Definition: x mbar = (0.001 x) bar
Wolfram Language: "Millibars"
QuantitiesDisplay Units
Fugacity, Pressurembar
mi — international mile
Symbol: mi
Definition: x mi = (1760 x) yd
Wolfram Language: "Miles"
Derived units: mph
QuantitiesDisplay Units
Length, SLength, Wavelengthmi
min — minute
Symbol: min
Definition: x min = (60 x) s
Wolfram Language: "Minutes"
Derived units: h, rpm
mph — miles per hour
Symbol: mph
Definition: x mph = x mi/h
Wolfram Language: "Miles" / "Hours"
QuantitiesDisplay Units
Velocitymph
nmi — nautical mile
Symbol: nmi
Definition: x nmi = (1852 x) m
Wolfram Language: "NauticalMiles"
Derived units: kn
Unit does not appear in the display units configured for any quantity.
Ω — ohm
Symbol: Ohm (prefixable)
Definition: x Ω = x V/A
Wolfram Language: "Ohms"
oz — avoirdupois ounce
Symbol: oz
Definition: x oz = (0.0625 x) lb
Wolfram Language: "Ounces"
Unit does not appear in the display units configured for any quantity.
ozf — ounce-force
Symbol: ozf
Definition: x ozf = (0.0625 x) lbf
Wolfram Language: "OuncesForce"
Pa — pascal
Symbol: Pa (prefixable)
Definition: x Pa = x N/m2
Wolfram Language: "Pascals"
Derived units: atm, bar
% — per cent
Symbol: percent
Definition: x % = (0.01 x) 1
Wolfram Language: "Percent"
‰ — per mille
Symbol: permille
Definition: x ‰ = (0.001 x) 1
Wolfram Language: "PerMil"
phon — phon
Logarithmic unit of loudness.
Symbol: phon
Base unit
Wolfram Language: "Phons"
QuantitiesDisplay Units
LoudnessLevelphon
ppm — parts per million
Symbol: ppm
Definition: x ppm = (1e-06 x) 1
Wolfram Language: "PartsPerMillion"
psi — pound-force per square inch
Symbol: psi
Definition: x psi = x lbf/in2
Wolfram Language:
"PoundsForce" / Power["Inches", 2]
QuantitiesDisplay Units
Fugacity, Pressurepsi
Definition: x rad = x 1
Derived units: rev, °
Rd — rutherford
Symbol: Rd (prefixable)
Definition: x Rd = (1e+06 x) Bq
Wolfram Language: "Rutherfords"
QuantitiesDisplay Units
Activity, RateRd
rem — roentgen equivalent man
Symbol: rem (prefixable)
Definition: x rem = (0.01 x) Sv
Wolfram Language: "Rems"
QuantitiesDisplay Units
DerPressureByDensity, DoseEquivalentrem
rev — revolution
Symbol: rev
Definition: x rev = (6.28319 x) rad
Wolfram Language: "FullAngle"
Derived units: rpm, Hz/2π
QuantitiesDisplay Units
AngularFrequency, AngularVelocity, Raterev/min
Hz/2π — revolution hertz
Symbol: revHz (prefixable)
Definition: x Hz/2π = x revHz
Wolfram Language: "FullAngle" / "Seconds"
QuantitiesDisplay Units
AngularFrequency, AngularVelocity, RateHz/2π
rpm — revolutions per minute
Symbol: rpm
Definition: x rpm = x rev/min
Wolfram Language: "FullAngle" / "Minutes"
QuantitiesDisplay Units
AngularFrequency, AngularVelocity, Raterpm
s — second
Symbol: s (prefixable)
Base unit
Wolfram Language: "Seconds"
Derived units: W, Bq, min, kat, N, Wb, Hz, dyn, C
S — siemens
Symbol: S (prefixable)
Definition: x S = x A/V
Wolfram Language: "Siemens"
sone — sone
Linear unit of loudness.
Symbol: sone
Base unit
Wolfram Language: "Sones"
QuantitiesDisplay Units
Loudnesssone
Symbol: sr (prefixable)
Definition: x sr = x m2/m2
Derived units: lm
st — stone
Symbol: stone
Definition: x st = (14 x) lb
Wolfram Language: "Stones"
Unit does not appear in the display units configured for any quantity.
Sv — sievert
Symbol: Sv (prefixable)
Definition: x Sv = x J/kg
Wolfram Language: "Sieverts"
Derived units: rem
QuantitiesDisplay Units
DerPressureByDensity, DoseEquivalentmSv, Sv
T — tesla
Symbol: T (prefixable)
Definition: x T = x Wb/m2
Wolfram Language: "Teslas"
Btuₜₕ — Thermochemical British thermal unit
Symbol: TCBtu
Definition: x Btuₜₕ = x callb°Rk/(gK)
Wolfram Language:
"ThermochemicalBritishThermalUnits"
Derived units: kBtuₜₕ
QuantitiesDisplay Units
Energy, WorkBtuₜₕ
kBtuₜₕ — 1000 Thermochemical British thermal unit
Symbol: TCkBtu
Definition: x kBtuₜₕ = (1000 x) Btuₜₕ
Wolfram Language:
"Kilo" "ThermochemicalBritishThermalUnits"
QuantitiesDisplay Units
Energy, WorkkBtuₜₕ
UKfloz — imperial fluid ounce
Symbol: UKfloz
Definition: x UKfloz = (28.4131 x) mL
Wolfram Language: "FluidOuncesUK"
Derived units: UKgal
Unit does not appear in the display units configured for any quantity.
UKgal — imperial gallon
Symbol: UKgal
Definition: x UKgal = (160 x) UKfloz
Wolfram Language: "GallonsUK"
QuantitiesDisplay Units
DerEnergyByPressure, VolumeUKgal
var — volt-ampere reactive
Note: It is debated whether this should be a base unit or not.
Symbol: var (prefixable)
Definition: x var = x VA
Wolfram Language: "VAs"
QuantitiesDisplay Units
Powervar
Wb — weber
Symbol: Wb (prefixable)
Definition: x Wb = x Vs
Wolfram Language: "Webers"
Derived units: H, T
yd — yard
Symbol: yd
Definition: x yd = (3 x) ft
Wolfram Language: "Yards"
Derived units: mi
QuantitiesDisplay Units
Length, SLength, Wavelengthyd
yr — vague year
365 days.
Symbol: yr
Definition: x yr = (365 x) d
Wolfram Language: "Years"
QuantitiesDisplay Units
1/Modelica.Units.SI.Time, DecayConstant, Rate1/yr
Timeyr