# வார்ப்புரு:Convert/doc



**Template ** *calculates* from one measurement unit to another one, and then *presents* the results formatted. For example:  
:<code></code> → <small>(km entered, so converted into mile)</small>  
:<code></code> → <small>(mi entered, so converted into km)</small>  

*Numbers* can be rounded, *units* can be abbreviated into symbols:  
:<code></code> →  
:<code></code> →  
Value *ranges* can be entered using <code>|to|...</code> or <code>|-|...</code>:  
:<code></code> →  
:<code></code> →  

Combined effect example:  
:<code></code> →  
:<code></code> →  

## Units to convert

Enter units to convert *from*&nbsp;*into*:  
- <code></code> →
:SI units generally accept prefixes, like "m" for milli (10<sup>−3</sup>), and "M" for mega (10<sup>6</sup>)  
:For "per" units, use "/" (slash): kg/ha  
:For three-unit units, etc., see  

## Unit name or symbol (abbreviation): *1 pound* or *1 lb*?
By default, the first quantity shows the unit name, the second shows the symbol (or abbreviation):  
- <code></code> →

Using is the *reverse behaviour* to the default:  
- <code></code> →

To abbreviate both or neither:  
- <code></code> →
- <code></code> →

### Convenience: has by default
Template is the same as , except that it has as the default behaviour. In , all other options are available. So:  
:<code></code> →  
is equivalent to:  
:<code></code> →  

## Adjective: *a 10-mile distance*
Use to produce the adjectival (hyphenated) form:  
- <code></code> → A distance.
Default behaviour, for comparison:  
- <code></code> → to go.

Even with , as per Manual of Style, no hyphen is produced with unit symbols.  

## Rounding: *100 ft* is *30&nbsp;m* or *30.5&nbsp;m* or *30.48&nbsp;m*?

By definition, 100&nbsp;ft equals . In practical use, it is common to round the calculated metric number. With that, there are several possibilities.  

### Default rounding
By default, the conversion result will be rounded either to precision comparable to that of the input value (the number of digits after the decimal point—or the negative of the number of non-significant zeroes before the point—is increased by one if the conversion is a multiplication by a number between 0.02 and 0.2, remains the same if the factor is between 0.2 and 2, is decreased by 1 if it is between 2 and 20, and so on) or to two significant digits, whichever is more precise. An exception to this is *rounding temperatures* (see below).  

| Examples of rounding |  |  |
| --- | --- | --- |
| **Input** | **Displays as** | **Note** |
| <code></code> |  |  |
| <code></code> | same output as with 0 (below) |  |
| <code></code> |  |  |
| <code></code> |  |  |
| <code></code> | The more-exact value is 37.4904 m or so, which gets converted to 37 m if this parameter is not specified at all. |  |
| <code></code> |  |  |
| <code></code> | same output as with −1 (above), because the conversion factor is between 0.2 and 2 (hence, it should produce same double-zero precision (−2) as in the input value), but the conversion must produce two significant digits at a minimum (hence, a higher single-zero precision (−1) is used) |  |
| <code></code> |  |  |
| <code></code> |  |  |
| <code></code> | exact value is 152.4 m |  |
| <code></code> |  |  |
| <code></code> | same output as with −3 (above), because the conversion factor is between 20 and 200 (hence, it should decrease input value's double-zero precision (−2) by 2), but the conversion must produce two significant digits at a minimum (hence, a higher triple-zero precision (−3) is used) |  |
| <code></code> | } |  |

*Convert* supports four types of rounding:  

### Round to a given precision: *use a precision number*
Specify the desired precision with the *fourth unnamed parameter* (or third unnamed parameter if the "convert to" parameter is omitted; or fifth unnamed parameter if a range is specified; or fourth unnamed parameter again if a range is specified and the "convert to" parameter is omitted; needs to be replaced with a "precision" named parameter). The conversion is rounded off to the nearest multiple of to the power of this number. For instance, if the result is 8621 and the round number is "-2", the result will be 8600. If the result is "234.0283043" and the round number is "0", the result will be 234.  

### Round to a given number of significant figures: **
To specify the output number to be with *n* significant figures use :  
- <code></code> →
- <code></code> →
- <code></code> →
- <code></code> →
Default behaviour, for comparison:  
- <code></code> →
Setting to a value less than 1 is meaningless:  
- <code></code> →

### Round to a multiple of 5: *15*, *20*, *25*, ...
Using rounds the outcome to a multiple of 5.  
- <code></code> →
- <code></code> →

Similar: using rounds the outcome to a multiple of 25.  
- <code></code> →
- <code></code> →
Default behaviour, for comparison:  
- <code></code> →

In a range, one can round *each value* individually to the default. Use :  
- <code></code> →
- <code></code> →

### <span id="Round to a multiple of a given fraction"></span>Round to a multiple of a given fraction: * inch*
Specify the desired *denominator* using . (Denominator is the below-the-slash number, for example the 3 in ).  
- <code></code> →
- <code></code> →
The fraction is reduced when possible:  
- <code></code> →
Default behaviour uses decimal notation:  
- <code></code> →

### Rounding temperatures: *°C*, *°F* and *K*
In temperatures, the conversion will be rounded either to the precision comparable to that of the input value or to that which would give three significant figures when expressed in kelvins, whichever is more precise.  

1. 
1. 
1. 
1. 
1. 
1. 

The precision of the input number in example (1) is one digit, but the precision of its Kelvins expression is three, so the precision of the Fahrenheit conversion is *made* three (made 180...) . (1) and (2) seem to belie the fact that a , and make the 32 degrees difference shown in (1) begin to seem off somehow.  
Result (1) seems off until you set the மதிப்புறு இலக்கங்கள் yourself with :  
:  
or you set the precision *positionally*, relative to the decimal point (zero being *at* the decimal point):  
:  

The precision of the input number in example (2) is six, so the precision of the Fahrenheit output is, whereas before, Kelvins had determined it to be three. Examples (3) and (4) show how this can be hidden and generate questions, but it occurs there because the Kelvins conversion generated two fractional parts. (Before it was the input number that generated the fractional part.) In example (3) the three input digits converted into five significant output digits because of the two digits after the decimal point, generated by the Kelvins conversion. This happened again in (5), but in (6) decimal fractions were neither given as input nor induced by the Kelvins conversion.  

### 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 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:  
- 
- 
- 
- 
Note that there is no or similar for rounding above the decimal place. Neither is there support for significant figures, multiples of 5, or any other output-rounding feature.  

The default precision is computed based on the input, so an explicit output precision must usually be supplied:  
- → (precisions are mismatched)
- →

In this case, if the input were rounded before conversion, a different result would be obtained:  
- → (double rounding)

## Into multiple units: **
Separate the multiple output units by a space:  
- <code></code> →
- <code></code> →
If the output unit names contain spaces, use <code>+</code> as the separator.  

See also:  
- For multiple-unit options like *1 ft 5 in*, see and .

## Ranges of values

A *range* converts *two* values and separates them by your choice of words and punctuation.  

### A range: *6 to 17 kg (13 to 37 lb)*
Range indicators are entered as the second parameter (between the values). Range separators can be:  

### Multiple dimensions: **
Use <code>by</code>:  
- <code></code> →

Use <code>×</code>, multiplication sign, or <code>x</code>, letter:  
- <code></code> →

In science, the formal way is to set <code>&#x7c;x&#x7c;</code> and (keeping dimensions , like in *area = x km<sup>2</sup>*):  
- <code></code> →

### Lists of values: *20, 40, or 60 miles*
:<code></code> &rarr;  

### About *feet, inch* in ranges and multiples
While it is possible to enter feet, inch in a simple conversion, this is not possible for ranges:  
- <code></code> →
Default behaviour, for comparison:  
- <code></code> →

## Words
### Spelling of unit name: UK *metre* or US *meter*?
Default spelling of units is en-UK. To show en-US spelling, use :  
:<code></code> → —*default*  
:<code></code> →  

### <span id="spell"></span>Spell out numbers: *ten miles*
To write a number in words, use :  
- <code></code> →

To spell out both in and out values, use :  
- <code></code> →

To make first letter a capital, use ,  
- <code></code> →
- <code></code> →

Remember that the spelling of the units (ft, m) is independently set by . To the extreme:  
- <code></code> →

### Inserted before units: *4 planted acres*
- <code></code> →
<code>disp=preunit</code> is similar, but has no separator after the specified text, and can have different text for the output value:  
- <code></code> →
- <code></code> →

### After adjective unit: *A corridor*
Note that two units (in this case, ft and m) are required. Use with just one unit will generate an error message.  
:<code></code> →  

### Plurals: *1&nbsp;inch, 2&nbsp;inches*
The unit symbol is singular always. Depending on the preceding number only, a unit name can be shown plural.  
- <code></code> →
- <code></code> →
- <code></code> →

;Exception:  
Entering the unit spelled <code>|foot|</code> forces singular output "foot", whatever the number is.  
- <code></code> →

### Fractions: *one-eighth of an imperial pint*
The convert template also supports spelling out fractions.  
- <code></code> →
Any additional words needed for the fraction can also be added at the end of the template.  
- <code></code> →

### Wrapping and line breaking
:See  

### <span id="million"></span>Spelling out "thousands", "millions", etc.
Most unit codes accept a prefix of e3 (thousand) or e6 (million) or e9 (billion).  
- <code></code> →
- <code></code> →
- <code></code> →

To display both input and output in scientific notation, use  
- <code></code> →

To spell out "thousands", "millions", etc., abbreviates the unit; displays both full unit names.  
- <code></code> →
- <code></code> →

## Numbers

### Using an SI prefix: *gigameter (Gm)*, or *micrometer (&#x03BC;m)*

Units can have an SI prefix like <code>G</code> before the unit: <code>Gm</code>, and <code>giga</code> before the name: <code>gigameter</code>. These are plain multiplication factors.  

To illustrate, these are trivial calculations (from meter to meter), showing the multiplication factor:  
- 
- 

The prefix can be added before the SI unit (here: unit <code>m</code> for meter):  
- <code></code> →
- <code>Mm</code>:
- <code>km</code>:
- <code>mm</code>:
- <code>&#x03BC;m</code>:
- <code>um</code>: (letter "u" can be used for "&#x03BC;" here)

The prefix can be used in the output unit:  
- <code></code> →
- <code></code> →

As an exception, the non-SI unit "inch" can have the "&#x03BC;" prefix too)  
- <code></code> →

### Engineering notation: *7 × 10<sup>6</sup> m*

#### In the unit: *e6m*
Engineering notation can be entered as a "prefix" to the unit:  
- <code></code> →

The same is possible for the output unit:  
- <code></code> →

Any standard unit (not a combination, multiple, or built-in unit) can have such a prefix:  
- <code>e3</code> (thousand),
- <code>e6</code> (million),
- <code>e9</code> (billion),
- <code>e12</code> (trillion),
- <code>e15</code> (quadrillion).

### Scientific notation: *1.23 × 10<sup>−14</sup>*
In அறிவியல் குறியீடு, a number is written like . The plain number has exactly one digit before the decimal point.  

With , the input can be in e-notation such as <code>12.3e4</code>. This value is displayed as a power of ten, and the output is displayed in scientific notation, except that an output value satisfying 0.01 <= v < 1000 is shown as a normal number. In addition, if the output value is 1000 and sigfig=4 is used, the value is displayed as a normal number.  
- <code></code> →
- <code></code> →

### Input with fractions: **
The number to convert can be written in fractions. Both <code>/</code> (keyboard slash) and <code>⁄</code> (fraction slash) are accepted:  
- <code></code> →
- <code></code> →

With positive பின்னம்s (a positive integer and a fraction), use a <code>+</code> sign  
- <code></code> →

With negative mixed numbers, use a hyphen <code>-</code> and repeat it:  
- <code></code> →

Note that the following cases are not interpreted as mixed numbers:  
- <code></code> → . This is interpreted as a range from 2 inches to 1⁄2 inch.
- <code></code> → This is neither a mixed number nor a range, and mathematical expressions requiring calculations are not allowed here.

### Output with horizontal fraction bar in: *&nbsp;inch*

Using a double slash (<code>//</code>) returns a horizontal bar fraction:  
- <code></code> →
- <code></code> →

### Thousands separator: *1,000 mi* or *1000 mi*
In input, a comma for thousands separator is accepted but not required; a gap (space) is not accepted. In output, by default, the thousand separator is the comma:  
- <code></code> →
- <code></code> →
- <code></code> →

Set to remove the separator from the output:  
- <code></code> →

Use to use digit grouping by gap (thin space) as a thousands separator:  
- <code></code> →
Default behaviour, for comparison:  
- <code></code> →

Setting will only add the separator when the number of digits is 5 or more:  
- <code></code> →
- <code></code> →
Default behaviour, for comparison:  
- <code></code> →

## Output manipulation
### Brackets and separators: *10 m [33 ft]*
Punctuation that distinguishes the two measurements is set by .  

Options are: <code>b</code> <small>(the default)</small>, <code>sqbr</code>, <code>comma</code>, <code>or</code>, <code>br</code>, <code>x…</code>:  
- <code></code> →
- <code></code> →
- <code></code> →
Default behaviour, for comparison:  
- <code></code> →

Setting will force a new line (<code>&lt;br/></code>)  
- <code></code> →

Also will force a new line, and keep the brackets (useful in tables):  
- <code></code> →

Setting allows any text as separator:  
- <code></code> → <small>(To display spaces, use <code>&amp;nbsp;</code>)</small>

### <span id="flip"></span>Flipping (reordering) the two measurements: **
Setting will flip (swap) the two measurements:  
- <code></code> →
Default behaviour, for comparison:  
- <code></code> →

When converting to multiple units, the effect is:  
- <code></code> →
- <code></code> →

### Fixed ordering of output units: **
Setting shows the output-units as ordered; the input unit is skipped:  
- <code></code> &rarr;
- <code></code> →

*See also: § Displaying parts of the output*.  

### Displaying parts of the result: **
It is possible to display only parts of the conversion result:  

| <code></code> | Regular output (for comparison) |  |
| --- | --- | --- |
| <code></code> | Input and output numbers |  |
| <code></code> | Input unit |  |
| <code></code> | Input unit, adjective (hyphenated) |  |
| <code></code> | Input (*workaround*. ) |  |
| <code></code> | Input: both name and symbol |  |
| <code></code> | Output unit (symbol) |  |
| <code></code> | Output unit (name) |  |
| <code></code> | Output value |  |
| <code></code> | Output value and unit name |  |
| <code></code> | Output value and unit symbol | } |

### Display both input name and symbol: *2 kilopascals [kPa]*
Setting returns both name and symbol of the first (input) unit:  
- <code></code> →
- <code></code> →

## Table options
For the structure, there are three options: add a line-break, split the result over columns and make the table sortable.  

### Enforced line break
adds a line-break and omits brackets.  

adds a line-break and does add brackets to the converted value. This may be useful in tables:  

### Table columns showing numbers only
Using {convert} in a table cell, with splits the result over two columns:  
:<code></code> →  
::<code></code>  

does the same, and also centers the text:  
:<code></code> →  
::<code></code>  

The units are added as a column header:  
:{| class=wikitable  
! | &nbsp;  
! | m  
! | ft  
|-  
|-  
|-  
| <small>(default)</small>  
|}  

### Sorting
Use to include a *hidden numerical sortkey* in the output, suitable for use in a . Technically, this places a hidden string before the actual displayed values:  
:<code></code>  
:showing: .  

Use both and together to produce table columns (pipe symbols) for each value in sortable columns:  

:{|  
!  
! m  
! ft  
|-  
| A  
|-  
| B  
|-  
| C  
|-  
| D  
|}  

The generated sortkey is calculated in a consistent way based on both the value and its unit as passed to the convert template. In most cases convert uses the passed value converted to SI base units. It is therefore not necessarily the displayed value or other alternate units and is calculated regardless of output format options. Using different units or different order of units in individual rows should therefore not lead to incorrect sorting, although variations in rounding can give surprising results, since an unrounded number is used for the sortkey.  

## Units
The conversion factors and physical constants are sourced here.  

### All units

### 'per' units: *kg/hl*, *miles per gallon*
When using a slash (<code>/</code>), a unit like <code>kg/hl</code> is recognized as kilograms *per* hectolitre and will be converted with other mass/volume units.  
- <code></code> →

Population density (*inhabitants per square mile*) can be converted using  
- <code></code> →

Vehicular fuel efficiency, commonly expressed in *miles per gallon* or *litres per 100 km* can also be converted  
- <code></code> →

### Units of difference: Expressing a change or difference in temperature
We have already discussed standard temperature conversions (°C, °F, K), as shown in these two examples:  
- (standard temperature conversion)
- (standard temperature range conversion)

When expressing a temperature *change* (e.g., "The temperature *increased* by 10&nbsp;°C"), or when *comparing* temperatures (e.g., "10 to 15&nbsp;°C *warmer*"), we cannot use the standard temperature units (, and ), which refer to points on the respective scale. Instead, we must use one of the following "units of difference": , and .  

Compare the following two examples with the two above:  

- increase in temperature
- warmer than normal

To produce multiple units in the output:  
- difference

### Multiple units: *1 ft 5 in*
#### In input
Base document lists options for *multiple unit input* (like <code>ft,in</code>). It can catch predefined sets only (units that can be subdivided; e.g., yd into ft):  
- <code></code> →
- <code></code> →
- <code></code> →

#### In output
Available multiple-unit output options predefined, like <code>ftin</code> and <code>ydftin</code>. The full list is at .  
- <code></code> →
- <code></code> → , using a space, returns the decimal point
Default behaviour, for comparison:  
- <code></code> →

See also:  
- a length used to measure horses
- a weight in ton, cwt, qr and lb

### Currency per unit: *$/mi &rarr; $/km*
Using currency symbols in a *$ per unit* value, you can convert the per-unit:  
- <code></code> →
- <code></code> →

You can set the currency in *both* values using :  
- <code></code> →

It is *not* possible to convert the currency. So, this result (mixed currencies) is *not* possible:  

## Using convert inside templates
For usage in template code, like infoboxes, has these options:  
;Pre-formatting fraction input  
- Module:Convert/helper can read regular input and pre-format it into -accepted input.
:Your template can accept and use &rarr;  

;Using a Wikidata property  
- Adding the Wikidata property code, like code , to your template code automatically returns the Wikidata property for that article, and convert it. Both number and unit are read.
Note: to return that property value for an *other* article, use .  

Example for :  
Note: this example uses (testing for )  
- <code></code> &rarr;
- <code></code> &rarr;
- <code></code> &rarr;
:For example see template:Infobox Telescope.  

Sometimes a property may have more than one value against in in Wikidata. You can use the parameter to specify which of the values you want to use.  

Example for :  
Note: this example uses (testing for )  
- : <code></code> →
- : <code></code> →

## Parameter list

## Deprecated options

## TemplateData

<templatedata>  
{  
"description": "Converts measurements to other units.",  
"params": {  
"1": {  
"label": "Value",  
"description": "The value to convert.",  
"type": "number",  
"required": true  
},  
"2": {  
"label": "From unit",  
"description": "The unit for the provided value.",  
"type": "string/line",  
"example": "km",  
"required": true  
},  
"3": {  
"label": "To units",  
"description": "The units to convert into. Separate units by a space for multiple outputs. In an output unit, use + for a multiplication space.",  
"type": "string",  
"example": "mi nmi",  
"suggested": true  
},  
"4": {  
"label": "Precision or suffix",  
"description": "Significant digits after decimal dot or, if negative, exponent of ten.",  
"type": "number"  
},  
"lk": {  
"label": "Link units",  
"description": "Indication of what units to apply wikilinks to. Use “on” for all, “in” for the input unit, “out” for the output units, or “off” for of the units.",  
"default": "off",  
"type": "string",  
"example": "on"  
},  
"abbr": {  
"label": "Abbreviation",  
"description": "Display for the units: “on” to display all units using their unit symbols, “off” to display all units in full words, “in” to display the unit symbol for the input unit, “out” to display the unit symbols for the output units, “unit” to display unit symbols for both input and output units when using scientific notation, “values” for no units at all (neither unit symbols nor full words of units).",  
"default": "out",  
"type": "string",  
"example": "on, unit, in, out, off",  
"suggested": true  
},  
"sp": {  
"label": "Spelling",  
"description": "Spelling of units. Use “us” to display unit names using U.S. spelling.",  
"type": "string",  
"example": "us"  
},  
"adj": {  
"label": "Adjective",  
"description": "Whether to use adjectival form. Use “on” for singular unit name appended by a hyphen, “mid” to put conversion at end, or “off” (default) for no adjectival form.",  
"type": "boolean",  
"example": "on",  
"default": "off"  
},  
"disp": {  
"label": "Conversion",  
"description": "Display conversion result: “or”: after ‘or’, “x”: with custom prefix and suffix, “b”: in parentheses, “table”/“tablecen”, “output only”: alone, “output number only”: alone and without unit, “unit”: not at all but input unit; if the value is a number it is used as precision.",  
"type": "string",  
"example": "b",  
"deprecated": "use order=flip instead"  
},  
"order": {  
"label": "Ordering",  
"description": "“flip” returns converted value first, input value second.",  
"type": "string",  
"example": "flip"  
},  
"sigfig": {  
"label": "Significant figures",  
"description": "Indicates the number of significant figures to be used in rounding.",  
"type": "number"  
},  
"round": {  
"label": "Rounding output",  
"description": "The type of rounding. “5” rounds the output number to nearest multiple of 5, “25” to nearest multiple of 25, “each” rounds each number in a range.",  
"type": "number"  
},  
"comma": {  
"label": "Thousands separator",  
"description": "Sets or suppresses the use of thousands separators in the numbers. “off”: no separator; “gaps”: use space instead of comma as thousands separator; “5” and “gaps5”: only add thousands separator when the integral part of the number uses 5 positions or more (10,000 or more; if using comma as thousands separator, 1234 would produce '1234', 12345 would produce '12,345').",  
"default": "on",  
"type": "string",  
"example": "off"  
},  
"sortable": {  
"label": "Sort key",  
"description": "“on” generates a hidden sort key",  
"type": "string",  
"example": "on"  
},  
"spell": {  
"label": "spell numbers?",  
"description": "If used, spells input or input and output numbers in words, optionally capitalizing the first",  
"example": "'in', 'In', 'on', or 'On'",  
"type": "string"  
},  
"sing": {  
"type": "string",  
"deprecated": "use adj=",  
"label": "singular",  
"description": "If 'yes', uses singular form of units (deprecated)",  
"example": "yes"  
},  
"frac": {  
"label": "fraction",  
"description": "fraction as rounding unit",  
"type": "number"  
},  
"$": {  
"label": "currency symbol",  
"description": "sets currency symbol in both units",  
"example": "$=€ will show \" €10 per mile (€6.2/km)\"",  
"type": "string"  
},  
"input": {  
"label": "WD property",  
"description": "Reeds the property value of the item (article), then converts it",  
"example": " (P2046=area)",  
"type": "string"  
}  
},  
"format": "inline"  
}  
</templatedata>