Editing Template:Convert/doc (section)

===Using an SI prefix: ''gigametre (Gm)'', or ''micrometre (&#x03BC;m)''===
{| class="wikitable floatright"
|+ [[Metric prefix]]es
|-
! Text
! Symbol
! Factor
|-
|quetta
| style="text-align: center;" |Q
|10<sup>30</sup>
|-
|ronna
| style="text-align: center;" |R
|10<sup>27</sup>
|-
|yotta
| style="text-align: center;" |Y
|10<sup>24</sup>
|-
|zetta
| style="text-align: center;" |Z
|10<sup>21</sup>
|-
|exa
| style="text-align: center;" |E
|10<sup>18</sup>
|-
|peta
| style="text-align: center;" |P
|10<sup>15</sup>
|-
|tera
| style="text-align: center;" |T
| 10<sup>12</sup>
|-
|giga
| style="text-align: center;" |G
| 10<sup>9</sup>
|-
|mega
| style="text-align: center;" |M
| 10<sup>6</sup>
|-
|kilo
| style="text-align: center;" |k
|10<sup>3</sup>
|-
|hecto
| style="text-align: center;" |h
|10<sup>2</sup>
|-
|deca
| style="text-align: center;" |da
|10<sup>1</sup>
|-
| colspan=2 style="text-align: center;" |(none)
|style="padding-left:0.6em; text-align:left;" | &nbsp;1
|-
|deci
| style="text-align: center;" |d
|10<sup>&minus;1</sup>
|-
|centi
| style="text-align: center;" |c
|10<sup>&minus;2</sup>
|-
|milli
| style="text-align: center;" |m
|10<sup>&minus;3</sup>
|-
|micro
| style="text-align: center;" |μ
|10<sup>&minus;6</sup>
|-
|nano
| style="text-align: center;" |n
|10<sup>&minus;9</sup>
|-
|pico
| style="text-align: center;" |p
|10<sup>&minus;12</sup>
|-
|femto
| style="text-align: center;" |f
|10<sup>−15</sup>
|-
|atto
| style="text-align: center;" |a
|10<sup>&minus;18</sup>
|-
|zepto
| style="text-align: center;" |z
|10<sup>&minus;21</sup>
|-
|yocto
| style="text-align: center;" |y
|10<sup>&minus;24</sup>
|-
|ronto
| style="text-align: center;" |r
|10<sup>&minus;27</sup>
|-
|quecto
| style="text-align: center;" |q
|10<sup>&minus;30</sup>
|}
Units can have an [[metric prefix|SI prefix]] like <code>G</code> before the unit: <code>Gm</code>, and <code>giga</code> before the name: <code>gigametre</code>. These are plain multiplication factors.

To illustrate, these are trivial calculations (from metre to metre), showing the multiplication factor:
* {{convert|12|Gm|m|abbr=on}}
* {{convert|12|μm|m|abbr=on}}

The prefix can be added before the SI unit (here: unit <code>m</code> for metre):
* <code><nowiki>{{convert|12|Gm|mi|abbr=on}}</nowiki></code> → {{convert|12|Gm|mi|abbr=on}}
* <code>Mm</code>: {{convert|12|Mm|mi|abbr=on}}
* <code>km</code>: {{convert|12|km|ft|abbr=on}}
* <code>mm</code>: {{convert|12|mm|in|abbr=on}}
* <code>&#x03BC;m</code>: {{convert|12|μm|mm|abbr=on}}
* <code>um</code>: {{convert|12|um|mm|abbr=on}} (letter "u" can be used for "&#x03BC;" here)

The prefix can be used in the output unit:
* <code><nowiki>{{convert|12000|mi|Mm|abbr=on}}</nowiki></code> → {{convert|12000|mi|Mm|abbr=on}}
* <code><nowiki>{{convert|12|in|μm|abbr=on}}</nowiki></code> → {{convert|12|in|μm|abbr=on}}

As an exception, the non-SI unit "inch" can have the "&#x03BC;" prefix too:
* <code><nowiki>{{convert|12|&#x03BC;m|μin|abbr=on}}</nowiki></code> → {{convert|12|μm|μin|abbr=on}}

{{further|Help:Convert units#SI prefixes}}