Editing Template:Convert/doc (section)

===Rounding input===
There is limited support for rounding the displayed ''input'' number.  The rounding takes place ''after'' conversion, so the output is based on the full-precision input.  This is useful when the input is produced by {{tlc|&#35;expr:}} or otherwise available to a higher precision than is usefully displayed, and it's desirable to avoid double-rounding.

To round the input to a specified number of digits after the decimal point, use one of the parameters:
* {{para|adj|ri0}}
* {{para|adj|ri1}}
* {{para|adj|ri2}}
* {{para|adj|ri3}}
Note that it is not possible to round above the decimal place ({{para|adj|ri-1}}{{nay}} is invalid). Neither is there support for significant figures, multiples of a number, or any other output-rounding feature.

The default precision is computed based on the input, so an explicit output precision must usually be supplied:
* {{tlc|convert|4.14159|mi|km|adj{{=}}ri0}} → {{convert|4.14159|mi|km|adj=ri0}} {{nay}} (precisions are mismatched)
* {{tlc|convert|4.14159|mi|km|0|adj{{=}}ri0}} → {{convert|4.14159|mi|km|0|adj=ri0}} {{aye}}

In this case, if the input were rounded before conversion, a different result would be obtained:
* {{tlc|convert|<nowiki>{{#expr:4.14159 round 0}}</nowiki>|mi|km|0}} → {{convert|{{#expr:4.14159 round 0}}|mi|km|0}} {{nay}} (rounds intermediate calculation, giving a different result)