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International System of Quantities
Quantities and Units
The joint ISO and IEC international standard defining quantities, units, and mathematical notation used in science and engineering.
765 quantities238 math terms12 parts
llength·bwidth·hheight·dthickness·ddiameter·rradius·spath length·ddistance·r_Qradial distance·rposition vector·Delta rdisplacement·rhoradius of curvature·kappacurvature·Aarea·Vvolume·alphaangular measure·varthetarotational displacement·varphiphase angle·ii(Omega)solid angular measure·tduration·ii(bb(sf(v)))velocity·ii(sf(v))speed·ii(bb(sf(a)))acceleration·bb(omega)angular velocity·bb(alpha)angular acceleration·Tperiod duration·tautime constant·Nrotation·ffrequency·nrotational frequency·omegaangular frequency·lambdawavelength·sigmarepetency·bb(ii(k))wave vector·kangular repetency·c, ii(sf(v)), (v)phase velocity·c_"g", ii(sf(v))_"g", (v_"g")group velocity·deltadamping coefficient·Lambdalogarithmic decrement·alphaattenuation·betaphase coefficient·gammapropagation coefficient·mmass·rhomass density·sf(ii(v))specific volume·drelative mass density·rho_Asurface mass density·rho_llinear mass density·bb(ii(J))moment of inertia·pmomentum·bb(ii(F))force·bb(ii(F))_"g"weight·bb(ii(F_"s"))static friction force·bb(ii(F))_(rm(mu))kinetic friction force·bb(ii(F))_"rr"rolling resistance·bb(ii(F))_"D"drag force·bb(ii(I))impulse·bb(ii(L))angular momentum·bb(ii(M))moment of force·Ttorque·bb(ii(H))angular impulse·ppressure·p_"e"gauge pressure·sigmastress·sigma_"n"normal stress·tau_"s"shear stress·bb(ii(epsilon))strain·epsilonrelative linear strain·gammashear strain·varthetarelative volume strain·muPoisson number·Emodulus of elasticity·Gmodulus of rigidity·Kmodulus of compression·kappacompressibility·I_"a"second axial moment of area·I_"p"second polar moment of area·Zsection modulus·mu_"s"static friction coefficient·mukinetic friction factor·llength·bwidth·hheight·dthickness·ddiameter·rradius·spath length·ddistance·r_Qradial distance·rposition vector·Delta rdisplacement·rhoradius of curvature·kappacurvature·Aarea·Vvolume·alphaangular measure·varthetarotational displacement·varphiphase angle·ii(Omega)solid angular measure·tduration·ii(bb(sf(v)))velocity·ii(sf(v))speed·ii(bb(sf(a)))acceleration·bb(omega)angular velocity·bb(alpha)angular acceleration·Tperiod duration·tautime constant·Nrotation·ffrequency·nrotational frequency·omegaangular frequency·lambdawavelength·sigmarepetency·bb(ii(k))wave vector·kangular repetency·c, ii(sf(v)), (v)phase velocity·c_"g", ii(sf(v))_"g", (v_"g")group velocity·deltadamping coefficient·Lambdalogarithmic decrement·alphaattenuation·betaphase coefficient·gammapropagation coefficient·mmass·rhomass density·sf(ii(v))specific volume·drelative mass density·rho_Asurface mass density·rho_llinear mass density·bb(ii(J))moment of inertia·pmomentum·bb(ii(F))force·bb(ii(F))_"g"weight·bb(ii(F_"s"))static friction force·bb(ii(F))_(rm(mu))kinetic friction force·bb(ii(F))_"rr"rolling resistance·bb(ii(F))_"D"drag force·bb(ii(I))impulse·bb(ii(L))angular momentum·bb(ii(M))moment of force·Ttorque·bb(ii(H))angular impulse·ppressure·p_"e"gauge pressure·sigmastress·sigma_"n"normal stress·tau_"s"shear stress·bb(ii(epsilon))strain·epsilonrelative linear strain·gammashear strain·varthetarelative volume strain·muPoisson number·Emodulus of elasticity·Gmodulus of rigidity·Kmodulus of compression·kappacompressibility·I_"a"second axial moment of area·I_"p"second polar moment of area·Zsection modulus·mu_"s"static friction coefficient·mukinetic friction factor·
What is it?
ISO 80000 & IEC 80000 are the international standards that define quantities, units of measurement, and mathematical notation used across science, engineering, and commerce worldwide.
How to use
Browse by domain or part, search across all entries with /, navigate entries with arrow keys. Every entry has exportable citations and linked data.
Linked data
Each entry includes JSON-LD structured data, RFC 5141 URN identifiers, and machine-readable exports in BibTeX, RIS, and RDF Turtle formats.
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Quantities & Units
Parts 3–13 — physical quantities and their measurement units
∑
Mathematical Notation
16 subparts2-5
Variables & Functions
2-6
Elementary Geometry
2-7
Sets
2-8
Classical Logic
2-9
Axiomatic Set Theory
2-10
Numbers & Functions
2-11
Special Functions
2-12
Number Theory
2-13
Combinatorics
2-14
Functions
2-15
Combinatorial Analysis
2-16
Calculus
2-17
Vectors & Matrices
2-18
Coordinates & Tensors
2-19
Transforms & Operators
2-20
Special Functions II
Semantic Layer
32
Documents
ISO & IEC 80000 publication structure with clauses and provisions.
OWL
Ontology
OWL classes, SHACL shapes, and SKOS concepts for the ISQ domain.
264
Units & Dimensions
264 measurement units and 16 dimensions from UnitsML.