Wikidata:Units
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This is a page for giving whatever information is available about storing units in Wikidata. Beyond units, Wikidata needs to express similar concepts like numeric datatype, scientific notation, and descriptions of uncertainty in data.
Units list
[edit]Each unit (unit of measurement (Q47574)) is related to physical properties (physical quantity (Q107715)).
The SI units (SI base unit (Q223662)) are green colored.
Spatial dimensions
[edit]Length (length (Q36253))
[edit]Area (area (Q11500))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
square metre (Q25343) | square kilometre (Q712226) | area (P2046), watershed area (P2053), wing area (P2112) |
square centimetre (Q2489298) | ||
square millimetre (Q2737347) | ||
are (Q185078) | hectare (Q35852) |
Volume (volume (Q39297))
[edit]Time (time (Q11471)) and frequency (frequency (Q11652))
[edit]Quantities with unit of time represent a duration or time interval. To use a value representing a point in time (e.g. a date), use of time value is recommended.
Time interval (time interval (Q186081))
[edit]Frequency (frequency (Q11652))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
hertz (Q39369) | kilohertz (Q2143992) | frequency (P2144) |
megahertz (Q732707) | ||
gigahertz (Q3276763) |
Matter
[edit]Mass (mass (Q11423))
[edit]Density (mass density (Q29539))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
kilogram per cubic metre (Q844211) | gram per cubic centimetre (Q13147228) | density (P2054) |
Concentration (concentration (Q3686031))
[edit]Thermodynamics
[edit]Temperature (temperature (Q11466))
[edit]Pressure (pressure (Q39552))
[edit]Thermal capacity (heat capacity (Q179388))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
joule per mole kelvin (Q20966455) | specific heat capacity (P2056) |
Thermal conductivity (thermal conductivity (Q487005))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
watt per metre kelvin (Q1463969) | thermal conductivity (P2068) |
Mechanics
[edit]Speed (speed (Q3711325))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
kilometre per hour (Q180154) | speed (P2052), speed of sound (P2075) | |
metre per second (Q182429) | kilometre per second (Q4220561) | |
knot (Q128822) |
Kinematic viscosity (kinematic viscosity (Q15106259))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
stokes (Q1569733) | kinematic viscosity (P2118) | |
square metre per second (Q3332099) |
Electromagnetism, optics
[edit]Electrical conductivity (electrical conductivity (Q4593291))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
ampere per volt metre (Q20966435) | electrical conductivity (P2055) |
Luminosity (luminosity (Q105902))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
solar luminosity (Q843877) | luminosity (P2060) |
Chemistry
[edit]Enthalpy (enthalpy (Q161064))
[edit]Unit | With prefixes | Corresponding properties |
---|---|---|
joule per mole (Q13035094) | kilojoule per mole (Q752197) | molar fusion enthalpy (P2066), molar enthalpy of vaporization (P2116), combustion enthalpy (P2117) |
kilojoule per kilogram (Q21077849) |
Currency (currency (Q8142))
[edit]Dimensionless
[edit]Item | Corresponding properties |
---|---|
infection (Q166231) | number of cases (P1603) |
Reports
[edit]- Wikidata:Database reports/Units of measurements
- Wikidata:Database reports/Items with unit symbol
- Special:ListProperties/quantity
- Subclasses of "unit of measurement" (Q47574)
- Properties with Constraint:Units
Discussion list
[edit]Please add any discussions on this topic to this list -
- Wikidata:Requests for comment/Dimensions and units for the quantity datatype - proposal for which units should be implemented first for the 'number with unit' datatype.
- See the Phabricator tasks at right, and this one
- Wikidata:Project_chat/Archive/2014/09#Quantities_with_units
- Wikidata:Project_chat/Archive/2015/05#Open_for_SI-unit_properties
- Wikidata:Project_chat/Archive/2015/06#Unit-based_properties_-_a_work-around
- Wikidata:Property_proposal/Property_metadata#units_used_for_this_property
- Wikidata:Property_proposal/Generic#conversion_to_standard_unit
- Wikidata:Property_proposal/Generic#standard_unit
- Wikidata:Property_proposal/Generic#conversion_to_SI_base_unit
- "Units are live! \o/" mailing list announcement