# Wolfram Language & System 10.4 (2016)|Legacy Documentation

This is documentation for an earlier version of the Wolfram Language.
BUILT-IN WOLFRAM LANGUAGE SYMBOL

# Quantity

Quantity[magnitude,unit]
represents a quantity with size magnitude and unit specified by unit.

Quantity[unit]
assumes the magnitude of the specified unit to be 1.

## Details and OptionsDetails and Options

• Quantity has attribute HoldRest and preserves the structure of unit.
• The specified unit should be a string or operation of strings representing the Quantity expression's unit value.
• Quantity[unit] will produce a canonicalized Quantity with a magnitude of 1.
• Quantity expressions can be created by using the Ctrl+Equal free-form linguistics interface.
• Quantity will automatically attempt to parse an unknown unit string to its canonical form.
• Supported units include all those specified by NIST Special Publication 811.
• For purely numeric units, such as percents, Normal[expr] converts a Quantity object to an ordinary number.

## ExamplesExamplesopen allclose all

### Basic Examples  (4)Basic Examples  (4)

A Quantity represents a value associated with a specific unit:

 In[1]:=
 Out[1]=

Use Ctrl+Equal to enter quantities and units:

 In[2]:=
 Out[2]=

Compound unit expressions can also be found using Ctrl+Equal:

 In[3]:=
 Out[3]=

A unit can be a string or a product of strings:

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 Out[1]=
 In[2]:=
 Out[2]=

Valid unit specifications include a number of physical constants:

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 In[2]:=
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 In[3]:=
 Out[3]=

Quantity will automatically attempt to interpret an unknown unit string:

 In[1]:=
 Out[1]=
 In[2]:=
 Out[2]=
 In[3]:=