Template:Calculator

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This template is for creating interactive calculators. It requires the calculator gadget. The calculator works by default. You can opt out at: Preferences > Gadgets > Template Gadgets > Enables javascript Calculator template.

You can use this template multiple times on a page to make input widgets, with some of the widgets having formulas based on other widgets, like a spreadsheet.

You can use {{Calculator label}} to mark text as a label for a calculator widget.

Statistics for this template are available at [1]

Examples

{{calculator|id=a|default=2|size=4}} × {{calculator|id=b|default=2|size=4}} = {{calculator|id=c|formula=a*b|default=4|type=plain}}

produces:

2 × 2 = 4

{{calculator|id=km|type=number|size=9|default=1.609344|formula=miles*1.609344}} km = 
{{calculator|id=miles|type=number|size=9|default=1|formula=km/1.609344}} miles

produces:

1.609344 km = 1 miles

BMI calculator metric

You can put widgets inside a wikitable.

{| class="wikitable" style = "float: left; margin-left:15px;"
|+ Metric
|-
| {{calculator label|Weight|for=weightkg}} || {{calculator|id=weightkg|size=3|default=80}} kg
|-
| {{calculator label|Height|for=heightcm}} || {{calculator|id=heightcm|size=3|default=160}} cm
|-
| BMI || '''{{calculator|id=bmimetric|type=plain|formula=round(weightkg/pow(heightcm/100,2))|default=31|style=min-width:3ch;display:inline-block}} kg/m<sup>2</sup>'''
|}

Metric
Weight	80 kg
Height	160 cm
BMI	31 kg/m²

BMI calculator imperial

You can also put widgets inside an HTML table.

<table class="wikitable">
<tr><td>Imperial</td></tr>
<tr><td>Weight</td><td>{{calculator|id=weight|size=3}} lbs</td></tr>
<tr><td>Height</td><td>{{calculator|id=heightFeet|size=1}} feet {{calculator|id=heightInches|size=2}} inches</td></tr>
<tr><td>BMI</td><td>'''{{calculator|id=bmi|type=plain|formula=round(100*weight*703/pow(heightFeet*12+heightInches,2))/100}} kg/m<sup>2</sup>'''</td></tr>
</table>

Imperial
Weight	lbs
Height	feet inches
BMI	kg/m²

Other

mdwiki:CHA2DS2–VASc score

Buttons

When pressed, the {{calculator button}} updates a form field.

{{calculator button|contents=Click me!|for=buttoncount|formula=buttoncount+1|type=plain}} 

The button has been clicked {{calculator|type=plain|default=0|id=buttoncount}} times.

Click me!

The button has been clicked 0 times.

Labels

A {{calculator label}}

adds a text label to a calculator widget, improving its accessibility
when clicked, give focus to the input widget, especially helpful for small widgets
selects/deselects a checkbox/radio target.

{{calculator|type=checkbox|id=checklabelex}} {{calculator label|label=Please click this label|for=checklabelex}}

Please click this label

Formula

Formulas use normal math syntax, with english words representing other input boxes. e.g. sin(1+foo*2) would multiply the foo box by 2, add 1 and take the sine of the whole thing. All calculations are done using IEEE 754 double precision floating point numbers.

Supported operators

Operators supported include: +, -, *, ×, /, ÷, % (percent is the modulo operator). Exponentiation must use the pow() function.

Math functions

Math functions supported include: 'abs', 'acos', 'acosh', 'asin', 'asinh', 'atan', 'atan2', 'atanh', 'ceil', 'cos', 'cosh', 'exp', 'floor', 'hypot', 'log', 'log10', 'log2', 'max', 'min', 'pow', 'random', 'sign', 'sin', 'sinh', 'sqrt', 'tan', 'tanh', 'trunc'

These have the same definition as in javascript. In particular, that means that log() is log base-e. The exception is round, which we use our own definition of.

Additional functions

The following additional functions are supported which are not from javascript Math library:

and: Logical and of all arguments (can take more than 2). This operator short circuits like lua, and returns first false argument. Wrap in bool() if you want a 1 or a 0
bool: Return 0 if value is very close to 0 or NaN, otherwise 1
coalesce: return the first argument that is not NaN.
ifbetween: return either fourth or fifth argument depending on if the first argument is between the second or third argument. Comparison is not fuzzy. The last two arguments are optional and default to 1 and 0 respectively.
ifequal: If first and second argument are the same, accounting for floating point error. The last two arguments are optional and default to 1 and 0 respectively.
iffinite: if the first argument is finite return second argument, otherwise return third argument. The last two arguments are optional and default to 1 and 0 respectively.
ifgreater: return third or fourth argument depending on if first argument is > second argument. Comparison is fuzzy to account for floating point error. Use ifpositive() if you don't want that. The last two arguments are optional and default to 1 and 0 respectively.
ifgreaterorequal: return third or fourth argument depending on if first argument is >= second argument. Comparison is fuzzy to account for floating point error. Use ifpositive() if you don't want that. The last two arguments are optional and default to 1 and 0 respectively.
ifless: Return third or fourth argument depending on if first argument is < second argument. Comparison is fuzzy to account for floating point error. Use ifpositive() if you don't want that. The last two arguments are optional and default to 1 and 0 respectively.
iflessorequal: return third or fourth argument depending on if first argument is <= second argument. Comparison is fuzzy to account for floating point error. Use ifpositive() if you don't want that. The last two arguments are optional and default to 1 and 0 respectively.
ifnan: if first argument is not a number (NaN), return second argument, otherwise third argument. The last two arguments are optional and default to 1 and 0 respectively.
ifpositive: if first argument is ≥ 0 return second, otherwise return third. Note this does not account for floating point rounding. You can use this if you need precise control over the comparison. The last two arguments are optional and default to 1 and 0 respectively.
ifzero: if first argument is epsilon away from zero, return second argument, otherwise third argument. The last two arguments are optional and default to 1 and 0 respectively.
index: Allows treating variables like an array with an index evaluated at runtime. index( foo, 2+3 ) is the same as foo5. The first argument must be an identifier (Nested index() is not allowed). The second argument must evaluate to an integer greater than or equal to 0. If either of these two arguments are invalid, NaN is returned. The third argument is returned if the arguments are valid but the result references a variable that does not exist. If unspecified the third argument defaults to NaN.
jsround: Use javascript round. This does round half towards positive infinity with a precision of 0. See mdn docs
not: Return 1 if value is very close to 0 or NaN, otherwise 0
or: Logical or of all arguments (can take more than 2). This operator short circuits like lua, and returns first true argument. Wrap in bool() if you want a 1 or a 0
round: A round function. Unlike javascript round(), this implements round half away from zero ("commercial rounding"). It takes an optional second argument to say how many decimal digits to rount to. e.g. round( 3.125, 2 ) = 3.13, round( -3.125, 2 ) = -3.13.
xor: Logical exclusive or. Can only take 2 arguments, always return 1 or 0.

Numbers

Numbers can be

integers
decimals
scientific notation. For example: 1, 2.84543, 3.12E6, -5, 3.45×10⁻⁴⁵

Supported constants

Infinity
-Infinity
NaN
pi
π
EPSILON

No relational operators yet

At the moment, relational operators like ≤ or ≠ and IF statements are not supported. This might be added in a future version if needed. This can be worked around by using ifzero and ifpositive functions.

Scoping

If the calculator widgets are contained within an element with the class calculator-container, then the ids are scoped to this element. This allows you to use the same ids multiple times on the same page without them interfering with each other. If the scoping element has the attribute data-calculator-refresh-on-load="true", then the calculator widgets are refreshed on first page load before the user interacts with it.

For example:

	
<div class="calculator-container" data-calculator-refresh-on-load="true">
{{calculator label|scopedfield:}} {{calculator|type=text|id=scopedfield|default=3.14}}<br>
This formula is updated before user interaction: {{calculator|type=plain|formula=scopedfield|default=No value}}
</div>
This formula is not updated because it is in a different scope: {{calculator|type=plain|formula=scopedfield|default=No value}}

Produces the following:

scopedfield: 3.14
This formula is updated before user interaction: No value

This formula is not updated even after user interaction because it is in a different scope: No value

Instead of using the css classes directly, you can also use the {{Calculator ifenabled}} with the scoped parameter.

CSS

You can use CSS to adjust the display, either via TemplateStyles or inline styles.

For checkboxes and radio buttons, you can use the :checked pseudo selector. This can be very useful when combined with sibling css selectors (~) or :has()
You can look for the class names calculator-value-true and calculator-value-false. This is especially useful with the passthru type of field. See {{Calculator-hideifzero}} for an example.
You can target the data-calculator-field-value attribute. e.g. #calculator-field-fieldidhere[calculator-field-scopedfield^="3."] would select the field if it is >= 3.0 and < 4.0.
You can use css variables for more complex calculations (Only in inline styles)

Some examples:

Adjust color of border: 30

Superimpose an image with coordinates based on a calculator widget:

Height: 178 cm. Waist: 155 cm.

Codex

It is possible to make widgets be in MediaWiki (Codex) style instead of OS style. You can use most codex widgets that have a CSS-only version. See https://doc.wikimedia.org/codex/latest/components/demos/

Many codex style widgets have separate templates. When making a label, the {{Calculator label}} template has a parameter to output a codex style label

Template	Example
{{Calculator codex text}}	Label textShort description text 42
{{Calculator codex radio}}	This is a group of options First optionAdditional text describing the first option Second optionAdditional text describing the first option Thid option
{{Calculator codex checkbox}}	First optionAdditional text describing the first option
{{Calculator codex toggle}}	My toggleAdditional text describing the toggle
{{Calculator button}}	default progressive destructive default progressive destructive

See the individual template doc pages for all the options.

Fallback

Users who do not have the gadget enabled in their preferences or have JS disabled, will not see the input boxes. Instead they will just see the default value for each box. With a good choice of default, this can be sufficient.

For example, if you have ''sin({{calculator|id=sine|type=text|default=0.5|size=4}}π)={{calculator|type=plain|default=1.00|decimals=2|formula=sin(sine*π)|id=sineres}}'' to make sin(0.5π)=1.00, the non-js user will lose the interactivity, but they will still see the equation.

If you want more sophisticated fallbacks, you can use the calculatorgadget-enabled and calculatorgadget-fallback CSS classes.

<div class="calculatorgadget-enabled" style="display:none">This text is only shown if the gadget is enabled. {{calculator|type=text|size=20|default=100|id=xyz}} </div>
<div class="calculatorgadget-fallback">This text is only shown if the gadget is disabled</div>

Which produces:

This text is only shown if the gadget is disabled

Alternatively, you can use the {{Calculator ifenabled}} template to do this.

Template arguments

For all types

id: The id for this field, English characters only, used in formulas of other fields. It must be unique on the page. Can be omitted if the field is not used as a value in any formulas.
default: The starting value
formula: The formula to calculate this field. See above for what is supported
placeholder: Placeholder text that shows up light grey when there is no input
readonly: Make field read only
size: how big to make the input box (In terms of number of letters that can fit in the box)
style: Custom CSS to use for the element.
class: Extra class to add to the element
class-live: CSS class to add only if the gadget is active on the page. Added after widgets are processed.
type: Type of field. Currently supported are number, text, plain, radio, checkbox, range, hidden, passthru.

checkbox	1Wet
	0 Big
hidden	160 Not visible, does not take space. Useful for intermediate results in formulas.
number	80
passthru	Is not visibly changed but the css class changes based on the formula User:Bawolff, I've set the formula to =wet, the checkbox above. Now what should happen?
plain	2
radio	1 Metric
	0 Imperial
text	160
range	160 160

Checkbox, hidden and radio can be useful in combination with TemplateStyles to hide and show fields, see Template:Body_roundness_index and Template:BMI calculator2/bmi.css for an example.

For number and range type only

max: Max number allowed (number type only)
min: Min number allowed (number type only)
step: How big the interval is for type=number and type=range inputs. Can be a number or the value "any"

For radio type only

name: When using type=radio, the name of the radio group.

For plain and text type

decimals: Format field to this many decimal digits. (Only works type=plain and type=text)
exponential-precision: Format field to this many significant digits in scientific notation. (Only works type=plain and type=text)
NaN-text: Use this text instead of NaN when result is not a number (Only works type=plain and type=text)
precision: Format field to this many significant digits. (Only works type=plain and type=text)

Add a calculator widget to the page. Like a spreadsheet you can refer to other widgets in the same page.

Template parameters[Edit template data]
Parameter		Description	Type	Status
id	`id`	The id for this input. This is used to reference it in formula of other calculator templates	String	required
type	`type`	What type of input box Suggested values `plain` `number` `text` `radio` `checkbox` `passthru` `hidden` `range`	String	required
formula	`formula`	Formula to calculate this field Example 3*log(a)	String	suggested
readonly	`readonly`	Make input box readonly to user input	Boolean	optional
size	`size`	Size of input box (How many characters it will fit)	Number	optional
max	`max`	max number allowed (type=number inputs only)	Number	optional
min	`min`	min number allowed (type=number inputs only)	Number	optional
placeholder	`placeholder`	Text to put as a placeholder in empty input	String	optional
step	`step`	How much to increment a type=number input box Example 2.5	Number	optional
default	`default`	Default value for this field	String	suggested
style	`style`	CSS to style the input element with	String	optional
name	`name`	For type=radio what group to assign the radio button to	Unknown	optional
precision	`precision`	Format to this many significant digits, using decimal notation except for really large numbers [Only applies to type=number or type=plain] Example 2	Number	optional
exponential-precision	`exponential-precision`	Format to this many significant digits, using scientific notation [Only applies to type=number or type=plain] Example 2	Number	optional
decimals	`decimals`	Format to a fixed number of decimal digits [Only applies to type=number or type=plain] Example 2	Number	optional
NaN-text	`NaN-text`	Use this text instead of NaN to signify "not a number". Only applies to format=plain or format=text. Plaintext only; wikitext is not supported Example Invalid calculation	String	optional
class	`class`	CSS classes to add	String	optional
class-live	`class-live`	CSS class to add only if gadget is active on the page	String	optional

The above documentation is transcluded from Template:Calculator/doc.
Editors can experiment in this template's sandbox and testcases pages.
Add categories to the /doc subpage. Subpages of this template.