User:MinorProphet/Draft subpages/man convert

Posted by MinorProphet (talk) 10:58, 20 September 2015 (UTC)

This is an attempt to create a complete and inclusive Manual for {{convert}}. I think the need for such a manual exists, and I'm happy to have a go. Please let me know if I'm wasting my time, and in what way.

Purpose of this page

1. To arrive at a consensus for a standard, meaningful, and consistent nomenclature for the {{Convert}} template and its documentation.
2. To apply the nomenclature in a uniform style to a proposed manual, perhaps similar in style to:

• man ls or
• the DIR command from RDOS manual, p. 100 [pdf. 110]

or other similar approach suitable for adapting to {{convert}}.

Background

Having leaped in at the deep end by attempting to order the tables at Template:Convert/list of units, I have come to realise that the {{convert }} template is an unusually complex 1337 undertaking. I feel it could benefit greatly from a complete and inclusive manual along the lines of nixen man pages or the old MS-DOS 6.22 printed manual. I haven't really come across this idea in practice on WP or other MW operations. I have no axe to grind, as they say: absolutely no criticism is implied of anything or anyone. I may be trying to re-invent the wheel, or missing something vital on the road to Epic Fail. The talk page is open for comments.

I have a foolish(?) vision of a first-time user being able to use the template and the get the correct desired result first time, by working through a decent manual in which every unnamed and named parameter is comprehensively treated in full, with all the defaults and exceptions and mutually exclusive options/parameters/values/ and work-arounds and kludges explained and/or mouse-overed etc.

For example, every option could be arranged (in the order they occur as you fill/construct the template) in its own collapsed section, something like this empty demo:

Input options

Conversion-value {{convert|2|

Multiple conversion-values

Range-separators - by/x/to - formatted like List of Units {{convert|2|x|3|

Input unit-code, {{convert|2|x|3|kg involving:

List of units

unit-names

unit-symbols, etc.

Explanation of meaning of each column in List of Units

Output unit-codes {{convert|2|x|3|kg|lb

Multiple combination outputs etc. {{convert|2|x|3|kg|lb

Rounding-value {{convert|2|x|3|kg|lb|3

|sigfig=, |round= {{convert|2|x|3|kg|lb|sigfig=3

Output options

Explanation of left and right-hand sides of output, etc and all their wild combos.

abbr=

|abbr=out|in/on/off {{convert|2|x|3|kg|lb|sigfig=3|abbr=off

|abbr=out (default)

|abbr=in

|abbr=on

|abbr=off

adj=

|adj=in/out/shake_it_all_about

disp=

etc.

Mock-up of General outline of manual, based on the above list, cobbled together in under 2 minutes

Input options for {{convert}}
Separator	Convert	Result	NotesParameter list

Range-value separators for {{convert}}
Separator	Convert	Result	NotesParameter list

List of Units in {{convert}}
system	unit name	unit-code	unit-symbol	notes	default output conversion	multiple output unit-codes

Output options for {{convert}}
Option	=..	Description	Note

Output option: abbr for {{convert}}
Option	=..	Description	Note

Output option: adj for {{convert}}
Option	=..	Description	Note

I can't be alone in feeling that much of the template documentation on WP is frustratingly incomplete, having been perhaps written by and for the pizza-and-jolt-cola types who coded it in the first place. Pwnd. I have some experience in writing instructions user manuals, which is a different skill to coding.

In creating this page, I was partly prompted by the somewhat incomplete examples at Template:Convert. Although certainly helpful, I think that the page often only hints at the relatively complex task that awaits the unsuspecting standard user/WP editor (like me), with sub-standard logic or mathematical abilities. Sometimes section headings are hardly addressed in the examples, eg Rounding. On the other hand, I find the Help:Convert messages much more at useful explaining the specific problems involved.

Proposed manual for Convert

Basic operation - for beginners

There are four stages to using the {{convert}} template:

1. Decide on the value for conversion, and the units you want to convert from and to (given in column 2), and start filling in the template (input) with the relevant 'unit-codes' from column 3. These are the 'unnamed parameters', with the last unnamed parameter being the number for rounding/precision (if required).
2. Decide how you want the results to be presented (output). The default output uses a mixture of full 'unit names' and 'unit-symbols' by adding various 'named parameters' such as |abbr= (also called 'display options', or simply 'options'). Click 'Show preview'.
3. Convert then calculates the measurements from one unit to the other.
4. Last, the template dynamically presents the results (output), depending on parameters (or 'display options') such as |abbr=

Example with defaults explained

NB: This is just ASCII art in a table, my technical ability stops not far from here. The terms like 'unnamed parameter' need changing, but this gives a general at-a-glance outline of what is needed.

Default input with basic 'input options' only : calculates the conversion

1st unnamed parameter: value for conversion

|     2nd unnamed parameter: 'unit-code' to convert from

|     |     3rd unnamed parameter: 'unit-code' to convert to

|     |     |            Default output : presents the results

|     |     |                    Left-hand side displays 'unit name' in full

|     |     |                    |         Converted value rounded to ?decimal places / ?sig. figures

|     |     |                    |         |    Right-hand side displays abbreviated 'unit-symbol'

↓    ↓    ↓                   ↓        ↓    ↓

{{convert|1|kg|lb}} → 1 kilogram (2.2 lb)

{{convert|1|lb|kg}} → 1 pound (0.45 kg)

Every unit-code has a default unit to convert to: see column 6. Litres convert by default to → imperial gallons, kilometres → miles, grams → ounces, etc. You can leave out the third unnamed parameter if you only want the default conversion.

|     |     3rd unnamed parameter not needed for default conversion!

↓    ↓    ↓

{{convert|1|kg}} → 1 kilogram (2.2 lb)

{{convert|1|lb}} → 1 pound (0.45 kg)

NB! Column 6 shows the two units as standard written abbreviations, thus: 1.0 kg (2.2 lb).

However, only the unit-codes in column 3 can/must be used as unnamed parameters.

Parameters (or options)

The {{convert}} template deals with and converts between units of measurement. However, it's best not to think too much about the word 'unit' by itself, since the term is used in three very specific ways within the documentation: 'unit-code', 'unit name', and 'unit-symbol', described below. The term 'parameter' is also frequently used, in terms such as 'unnamed parameter' and 'named parameter' (sometimes called 'option').

At least two 'unnamed parameters' are essential: 'named parameters' are optional, and alter the displayed result.

|-unnamed parameters--| |-----------named parameters------------|

|----- Input options -----| |------------Output options----------------|

↓      ↓      ↓    ↓    ↓          ↓           ↓               ↓             ↓

{{convert|36.21|km|nmi mi|5|abbr=out|sp=us|sigfig=3|lk=on}}

Input options

1st unnamed parameter: value to convert

|     2nd unnamed parameter: 'unit-code' (column 3) to convert from. For the default unit to convert to, see column 6

|     |     3rd unnamed parameter: 'unit-code' (column 3) to convert to. Not needed for default conversion, see column 6

|     |     |     4th & 5th unnamed parameters (NB no | separator): unit-code(s) for multiple conversion (see column 7)

|     |     |     |     |     last unnamed parameter: value for precision or rounding (whole number)

|     |     |     |     |     |

{{convert|1|kg|lb oz ozt|2}}

{{convert|1|kg|lb oz ozt|2}} → 1 kilogram (2.20 lb; 35.27 oz; 32.15 ozt)

Here are the conversions, without and with the named parameters:

{{convert|36.21|km|nmi mi|5}} → 36.21 kilometres (19.55184 nmi; 22.49985 mi)

{{convert|36.21|km|nmi mi|5|abbr=out|sp=us|sigfig=3|lk=on}} → 36.21 kilometers (19.55184 nmi; 22.49985 mi)

Convert normally uses British spelling for the 'unit names' (metre, kilometre). The notes in column 5 show the alternative U.S. spelling (meter, kilometer), which is enabled by using the |sp=us parameter/option.

Nomenclature (incomplete)

Maybe there is no advantage to this whole idea, it could be unworkable for various reason I have failed to grasp.

You got this far. This section hopes to arrive at a naming scheme. It's far from complete.

Divided into two main sections, unnamed and named parameters, with each parameter/option/etc. fully documented for each.

'Unnamed parameters' (or 'initial arguments' or 'input options' or something)

• 'Input-value' (or 'number to be converted') (required). (e.g. {{convert|2.71)
• 'Input unit-code' (required). The whole template (I think) is structured around the use of unit-codes. These are the basis of the master tables which are processed by a script to make the conversions. The unit-codes are shown in column 3.
  There must be at least one unit-code (the input, or l-h side unit-code).
  • (optional) 'value separators' like +, -, by,
  • 'Output unit-code' (optional). A typical conversion uses two unit-codes (input & output). If more than two output unit-codes are specified, do not use a separator between them.
  • 'Rounding-value'. (optional). This is a whole number which

• Every unit-code can be expressed in the displayed result (the output) either in words (the 'unit-name') or by an abbreviation ('unit-symbol').

List of Units - ideas

This should have comprehensive subsections dealing with each column and what it means, and how the info in each column can be used to customise the output. I found that understanding the meaning of each column in the List of units was very helpful for a beginner, and how the unit-codes in each section in the Master doc are the basis (I think) of the whole template.

• System
• 'unit-code', listed in column 3.
• 'unit-name'. The units to convert from and to are listed in column 2 of the following tables.
• 'unit-symbol'. (column 4) Abbreviations for output instead of full unit names
• Notes - Different types of alternative unit-codes:
  • micro-things with μ, degrees ° CKF, and Ångstrom.
  • US-specific things, requiring |sp=us
• Default conversion units for each unit-code
• Multiple output combos

Input - unnamed params

• 'unit-code' (column 3)

The {{convert}} template uses unit-codes, which are similar to (but not necessarily exactly the same as) the usual written abbreviation for a given unit. These 'unit-codes' are given in column 3 of the following tables, and are accepted as input by the {{convert}} template as the second and third unnamed parameters.

Output - named params

The units in the displayed result can be shown either in full (the 'unit name' given in column 2) or abbreviated (the 'unit-symbol' given in column 4)

Equivalent current nomenclature

NB Some duplication here...

Unnamed parameters

• unit-code for the unit to be converted from    = left-hand side = input parameter = 2nd unnamed parameter
• unit-code(s) for the unit(s) to be converted to = right-hand side = output parameter(s) = 3rd, 4th etc. unnamed parameter
• 'unit name' (column 2)
• 'unit-symbol' (column 4)
• rounding-value = last named parameter

Input options (Unnamed parameters)

Conversion value

The number to be converted. Can be expressed in:

• Scientific notation
• Engineering notation
• Fractions, with //

Input-codes

And how they relate to the unit names and unit-symbols

Range separators

Discusses the table and possible improvements

+ and - ("range separators"?)

I may be wrong, but I don't think that the list of Value range separators works in the same way as the Units list (possibly because it's not generated from a machine-readable source like Module:Convert/documentation/conversion data/doc?) I feel it could do with some re-jigging, to have similar/same columns as the Unit tables.

Rounding option (last unnamed parameter or 'rounding value')

Rounding factor

If the number is:

• negative, rounds to the nearest 10/100/1000
• 0, rounds to the nearest 1 ???
• positive, rounds to that number of significant digits (here be dragons!)

For non-mathematicians

If the result has unwanted trailing zeroes, eg 12.34500, reduce the "rounding value" by that number of trailing zeroes:

• {{convert|1.02875|ft|in|5}} → 1.02875 feet (12.34500 in)
• {{convert|1.02875|ft|in|3}} → 1.02875 feet (12.345 in)

Default: Uses the same precision as the conversion value (param 1). If no rounding value (or last unnamed parameter) is given, {{convert}} uses

• No value: outputs some random value, vaguely related to the actual number.
• If the value is a whole number, xxx?
• If the value has decimal places, then xxx? (The output uses the number of decimal places, including all trailing zeroes if the number of sig figs is greater than the exact number of decimal places with no trailing zeros - or something???)
• To display a specific number of significant figures, use |sigfig=<number>

The table below is an adaptation of the table at Significant figures#Rounding and decimal places, which I found very useful in trying to understand the difference. It uses a random value of 12.345, which is exactly 12 x 1.02875 inches: thus the trivial use of ft-in in convert.

I used {{convert}} to make the conversions to output the values in the table. But there's a difference (in one cell) between the original table and the ouput result of {{convert}}. Why? Is it a mistake, or does it highlight the differences between the two level of precision that convert uses?

{{Convert}} code for 'decimal places' after the point	Rounding to decimal places	Precision	Rounding to significant digits	{{Convert}} code for sigfigs for entire number
{{convert|1.02875|ft|in|7}}	12.3450000	7	12.34500	{{convert|1.02875|ft|in|sigfig=7}}
{{convert|1.02875|ft|in|6}}	12.345000	6	12.3450	{{convert|1.02875|ft|in|sigfig=6}}
{{convert|1.02875|ft|in|5}}	12.34500	5	12.345	{{convert|1.02875|ft|in|sigfig=5}}
{{convert|1.02875|ft|in|4}}	12.3450	4	12.35 2.34?!	{{convert|1.02875|ft|in|sigfig=4}}
{{convert|1.02875|ft|in|3}}	12.345	3	12.3	{{convert|1.02875|ft|in|sigfig=3}}
{{convert|1.02875|ft|in|2}}	12.35	2	12	{{convert|1.02875|ft|in|sigfig=2}}
{{convert|1.02875|ft|in|1}}	12.3	1	10	{{convert|1.02875|ft|in|sigfig=1}}
{{convert|1.02875|ft|in|0}}	12	0	12.3450	{{convert|1.02875|ft|in|sigfig=0}}
{{convert|1.02875|ft|in|-1}}	10	-1	12.3450	{{convert|1.02875|ft|in|sigfig=-1}}

• Default:

{{convert|1.02875|ft|in}} → 1.02875 feet (12.3450 in)

• display 5 decimal places, including all trailing zeroes:

{{convert|1.02875|ft|in|5}} → 1.02875 feet (12.34500 in)

• display 5 significant figures:

{{convert|1.02875|ft|in|sigfig=5}} → 1.02875 feet (12.345 in)

Other ideas for incorporating into the manual

• Proposed re-arrangement of the Range table to make it look and work just like the Unit tables - I don't think it does at the moment.
• + - as unnamed parameters
• ±Arguments/options/values/parameters
• Confirm exactly how rounding works...
• Last unnamed parameter = Rounding: "round number" should be "rounding number" or "number to round by" etc.
• etc.
• etc.

Sandbox (hidden)

NB The rest of this page is just rough stuff with DemoTemplate examples.

Convert/list of units

This has been transcluded (I hope) from Template:Convert/list of units.

The table below lists units supported by {{convert}}. More complete lists are linked for each dimension. For a complete list of all dimensions, see full list of units.

{{Convert}} uses unit-codes, which are similar to, but not necessarily exactly the same as, the usual written abbreviation for a given unit. These unit-codes are displayed in column 3 of the following tables. These are accepted as input by {{convert}} as the second and third unnamed parameters:

• {{convert|100|kg|lb}} → 100 kilograms (220 lb)
• {{convert|100|lb|kg}} → 100 pounds (45 kg)

The unit-codes should be treated as case-sensitive:

• {{convert|100|Mm|mm}} → 100 megametres (1.0×10¹¹ mm)

The output of {{convert}} can display multiple converted units, if further unit-codes are specified after the second unnamed parameter (without the pipe separator). Typical combination output units are listed below in column 7.

• {{convert|55|nmi|km mi}} → 55 nautical miles (102 km; 63 mi)
• {{convert|1|oz|ozt g gr}} → 1 ounce (0.91 ozt; 28 g; 440 gr)

Some units have alternative unit-codes. These are shown in brackets in column 3, e.g. °F (F). Either may be entered for Fahrenheit (but not a lower-case f).

Units

Explanation

Explanation

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
the system(s) to which the unit belongs	units listed by name	unit-code to use in template		symbols shown in output	other notes about the units	sample of the default conversion for the unit	output codes for multiple conversions

Area

Area
(Full list)

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
SI	square kilometre	km2		km2	US spelling: square kilometer	1.0 km2 (0.39 sq mi)	km2 sqmi
	square metre	m2		m2	US spelling: square meter	1.0 m2 (11 sq ft)	m2 sqft
	square centimetre	cm2		cm2	US spelling: square centimeter	1.0 cm2 (0.16 sq in)	cm2 sqin
	square millimetre	mm2		mm2	US spelling: square millimeter	1.0 mm2 (0.0016 sq in)	mm2 sqin
non-SI metric	hectare	ha		ha		1.0 ha (2.5 acres)
Imperial & US customary	square mile	sqmi		sq mi		1.0 sq mi (2.6 km2)	sqmi km2
	acre	acre		(none)		1.0 acre (0.40 ha)
	square yard	sqyd		sq yd		1.0 sq yd (0.84 m2)
	square foot	sqft (sqfoot)		sq ft	long code "sqfoot" outputs square foot (and never feet)	1.0 sq ft (0.093 m2)	sqft m2 (sqfoot m2)
	square inch	sqin		sq in		1.0 sq in (6.5 cm2)	sqin cm2
Other	square nautical mile	sqnmi		sq nmi		1.0 sq nmi (3.4 km2; 1.3 sq mi)
	dunam	dunam		(none)	For alternative spellings and definitions see the full list	1.0 dunam (0.0010 km2; 0.00039 sq mi)
	tsubo	tsubo		(none)		1.0 tsubo (3.3 m2)

Density

Density

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
Metric	kilogram per cubic metre	kg/m3		kg/m3		1.0 kg/m3 (1.7 lb/cu yd)	kg/m3 lb/ft3 (kg/m3 lb/cuft) kg/m3 lb/yd3 (kg/m3 lb/cuyd)
	gram per cubic metre	g/m3		g/m3		1.0 g/m3 (0.0017 lb/cu yd)	g/m3 kg/m3 g/m3 lb/ft3 (g/cm3 lb/cuft) g/m3 lb/yd3 (g/cm3 lb/cuyd)
Imperial & US customary	pound per cubic foot	lb/ft3		lb/cu ft		1.0 lb/cu ft (0.016 g/cm3)	lb/ft3 kg/m3 (lb/cu ft g/m3) lb/ft3 g/m3 (lb/cu ft g/m3)
	pound per cubic yard	lb/yd3		lb/cu yd		1.0 lb/cu yd (0.59 kg/m3)	lb/yd3 kg/m3 (lb/cuyd kg/m3) lb/yd3 g/m3 (lb/cuyd g/m3)

Energy

Energy
(Full list)

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
SI	gigajoule	GJ		GJ		1.0 GJ (280 kWh)
	megajoule	MJ		MJ		1.0 MJ (0.28 kWh)
	kilojoule	kJ		kJ		1.0 kJ (240 cal)
	hectojoule	hJ		hJ		1.0 hJ (24 cal)
	decajoule	daJ		daJ		1.0 daJ (2.4 cal)
	joule	J		J		1.0 J (0.24 cal)
	decijoule	dJ		dJ		1.0 dJ (0.024 cal)
	centijoule	cJ		cJ		1.0 cJ (0.0024 cal)
	millijoule	mJ		mJ		1.0 mJ (0.00024 cal)
	microjoule	μJ (uJ)		μJ		1.0 μJ (2.4×10−7 cal)
	nanojoule	nJ		nJ		1.0 nJ (2.4×10−10 cal)
cgs	megaerg	Merg		Merg		1.0 Merg (0.10 J)
	kiloerg	kerg		kerg		1.0 kerg (0.10 mJ)
	erg	erg		(none)		1.0 erg (0.10 μJ)
Watt-hour multiples	terawatt-hour	TWh		TWh		1.0 TWh (3.6 PJ)
		TW.h		TW⋅h
	gigawatt-hour	GWh		GWh		1.0 GWh (3.6 TJ)
		GW.h		GW⋅h
	megawatt-hour	MWh		MWh		1.0 MWh (3.6 GJ)
		MW.h		MW⋅h
	kilowatt-hour	kWh		kWh		1.0 kWh (3.6 MJ)
		kW.h		kW⋅h
	watt-hour	Wh		Wh		1.0 Wh (3.6 kJ)
		W.h		W⋅h
Electron- volt multiples
	gigaelectronvolt	GeV		GeV		1.0 GeV (0.16 nJ)
	megaelectronvolt	MeV		MeV		1.0 MeV (0.16 pJ)
	kiloelectronvolt	keV		keV		1.0 keV (0.16 fJ)
	electronvolt	eV		eV		1.0 eV (0.16 aJ)
	millielectronvolt	meV		meV		1.0 meV (0.16 zJ)
Calorie multiples	calorie	Cal		Cal	The thermo-chemical calorie is the default definition. For others, see the full list.	1.0 Cal (4.2 kJ)
	megacalorie	Mcal		Mcal		1.0 Mcal (4.2 MJ)
	kilocalorie	kcal		kcal		1.0 kcal (4.2 kJ)
	calorie	cal		cal		1.0 cal (4.2 J)
	millicalorie	mcal		mcal		1.0 mcal (4.2 mJ)
pound/ ounce-foot/ inch-hour-minute-second	foot-poundal	ftpdl		ft⋅pdl		1.0 ft⋅pdl (0.042 J)
	foot-pound force	ftlbf		ft⋅lbf		1.0 ft⋅lbf (1.4 J)
		ftlb-f		ft⋅lbf
	inch-pound force	inlbf		in⋅lbf		1.0 in⋅lbf (110 mJ)
		inlb-f		in⋅lbf
	inch-ounce force	inozf		in⋅ozf		1.0 in⋅ozf (7.1 mJ)
		inoz-f		in⋅ozf
	horsepower-hour	hph		hp⋅h		1.0 hp⋅h (0.75 kWh)
British thermal unit	British thermal unit	Btu		Btu	The International Steam Table British thermal unit is used. For others, see the full list.	1.0 Btu (1.1 kJ)
		BTU		BTU
TNT-based units	gigatonne of TNT	GtTNT		(none)		1.0 gigatonne of TNT (4.2 EJ)
	gigaton of TNT	GtonTNT		(none)
	megatonne of TNT	MtTNT		(none)		1.0 megatonne of TNT (4.2 PJ)
	megaton of TNT	MtonTNT		Mt
	kilotonne of TNT	ktTNT		(none)		1.0 kilotonne of TNT (4.2 TJ)
	kiloton of TNT	ktonTNT		kt
	tonne of TNT	tTNT		(none)		1.0 tonne of TNT (4.2 GJ)
	ton of TNT	tonTNT		(none)
Other
	Hartree	Eh		Eh		1.0 Eh (27 eV)
	rydberg	Ry		Ry		1.0 Ry (14 eV)
	tonne of oil equivalent	toe		toe		1.0 toe (42 GJ)
	barrel of oil equivalent	BOE		BOE		1.0 BOE (6.1 GJ)
	cubic foot of natural gas	cuftnaturalgas (cufootnaturalgas)			Unit-code cufootnaturalgas will show "cubic foot of natural gas" if plural.	1.0 cubic foot of natural gas (1.1 MJ)

Force

Force
(Full list)

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
SI	giganewton	GN		GN	Allows triple output units. See: full list.	1.0 GN (220,000,000 lbf)	GN LT-f GN LTf GN ST-f GN STf
	meganewton	MN		MN	Allows triple output units. See: full list.	1.0 MN (220,000 lbf)	MN LT-f MN LTf MN ST-f MN STf
	kilonewton	kN		kN	Allows triple output units. See: full list.	1.0 kN (220 lbf)	kN LT-f kN LTf kN ST-f kN STf
	newton	N		N		1.0 N (0.22 lbf)	N lb-f N lbf N oz-f N ozf
	millinewton	mN		mN		1.0 mN (0.0036 ozf)	mN oz-f mN ozf mN gr-f mN grf
	micronewton	μN (uN)		μN		1.0 μN (0.0016 grf)	μN gr-f μN grf
	nanonewton	nN		nN		1.0 nN (1.6×10−6 grf)	nN gr-f nN grf
cgs	megadyne	Mdyn		Mdyn		1.0 Mdyn (2.2 lbf)
	kilodyne	kdyn		kdyn		1.0 kdyn (0.036 ozf)
	dyne	dyn (dyne)		dyn		1.0 dyn (0.016 grf)
	millidyne	mdyn		mdyn		1.0 mdyn (1.6×10−5 grf)
Metric gravitational units	tonne-force	t-f		tf		1.0 tf (9.8 kN; 0.98 LTf; 1.1 STf)
		tf		tf
	kilogram-force	kg-f		kgf		1.0 kgf (9.8 N; 2.2 lbf)
		kgf		kgf
	gram-force	g-f		gf		1.0 gf (9.8 mN; 0.035 ozf)
		gf		gf
	milligram-force	mg-f		mgf		1.0 mgf (9.8 μN; 0.015 grf)
		mgf		mgf
Avoirdupois-based units	poundal	pdl		pdl		1.0 pdl (0.14 N)
	long ton-force	LT-f		LTf		1.0 LTf (10.0 kN)	LT-f ST-f
		LTf		long ton-force			LTf STf
	short ton-force	ST-f		STf		1.0 STf (8.9 kN)	ST-f LT-f
		STf		short ton-force			STf LTf
	pound-force	lb-f		lbf		1.0 lbf (4.4 N)
		lbf		lbf
	grain-force	gr-f		grf		1.0 grf (640 μN)
		grf		grf

Length

Length
(Full list)

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
SI	megametre	Mm		Mm	US spelling: megameter	1.0 Mm (620 mi)
	kilometre	km		km	US spelling: kilometer	1.0 km (0.62 mi)	km mi
	metre	m		m	US spelling: meter	1.0 m (3 ft 3 in)	m ft m ftin
	centimetre	cm		cm	US spelling: centimeter	1.0 cm (0.39 in)	cm in
	millimetre	mm		mm	US spelling: millimeter	1.0 mm (0.039 in)	mm in
	micrometre	μm (um)		μm	US spelling: micrometer	1.0 μm (3.9×10−5 in)
	nanometre	nm		nm	US spelling: nanometer	1.0 nm (3.9×10−8 in)
non-SI metric	ångström	Å (angstrom)		Å		1.0 Å (3.9×10−9 in)
Imperial & US customary	mile	mi		mi		1.0 mi (1.6 km)	mi km
	furlong	furlong		(none)		1.0 furlong (660 ft; 200 m)
	chain	chain		(none)		1.0 chain (66 ft; 20 m)
	rod	rd		rd	For other names of this unit see the full list.	1.0 rd (17 ft; 5.0 m)
	fathom	fathom		(none)	fathom ≡ 6 ft	1.0 fathom (6.0 ft; 1.8 m)
	yard	yd		yd	assumes the international definition	1.0 yd (0.91 m)
	foot	ft (foot)		ft	long code "foot" outputs foot (and never feet) Use of ′ and ″ symbols violates MOSNUM so is not provided.	1.0 ft (0.30 m)	ftin (feet and inches) ft m (foot m)
	inch	in		in	Use of ′ and ″ symbols violates MOSNUM so is not provided.	1.0 in (25 mm)	in cm in mm
Other	nautical mile	nmi		nmi	the international standard nautical mile For other nautical miles see the full list.	1.0 nmi (1.9 km; 1.2 mi)
	parsec	pc		pc		1.0 pc (3.3 ly)
	light-year	ly		ly		1.0 ly (63,000 AU)
	astronomical unit	AU		AU		1.0 AU (150,000,000 km; 93,000,000 mi)

Mass

Mass
(Full list)

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
SI	kilogram	kg		kg	Allows triple output units. See: full list.	1.0 kg (2.2 lb)	kg lb kg st
	gram	g		g		1.0 g (0.035 oz)	g oz
	milligram	mg		mg		1.0 mg (0.015 gr)	mg gr
	microgram	μg (ug)		μg		1.0 μg (1.5×10−5 gr)
non-SI metric	tonne	t		t	Allows triple output units. See: full list.	1.0 t (0.98 long tons; 1.1 short tons)	t LT t ST
	metric ton	MT		t			MT LT MT ST
Avoirdupois	long ton	LT		(none)	2,240 lb used mostly in the British Commonwealth. Allows triple output units. See: full list.	1.0 long ton (1.0 t)	LT t LT MT LT ST
		long ton		long ton
	short ton	ST		(none)	2,000 lb used mostly in the US. Allows triple output units. See: full list.	1.0 short ton (0.91 t)	ST t ST MT ST LT
		short ton		short ton
	stone	st		st	14 lb used previously in the British Commonwealth except Canada. Allows triple output units. See: full list.	1.0 st (14 lb; 6.4 kg)	st kg st lb
	pound	lb		lb	Allows triple output units. See: full list.	1.0 lb (0.45 kg)	lb kg lb st
	ounce	oz		oz		1.0 oz (28 g)	oz g
	drachm	drachm		(none)		1.0 drachm (1.8 g)
	drachm	dram		(none)
	grain	gr		gr	equivalent to the troy grain	1.0 gr (0.065 g)
Troy	troy ounce	ozt		ozt		1.0 ozt (1.1 oz; 31 g)
other	carat	carat		(none)		1.0 carat (0.20 g)

Speed

Speed
(Full list)

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
SI	metre per second	m/s		m/s	US spelling: meter per second	1.0 m/s (3.3 ft/s)	m/s ft/s (m/s foot/s)
non-SI metric	kilometre per hour	km/h		km/h	US spelling: kilometer per hour	1.0 km/h (0.62 mph)	km/h mph
Imperial & US customary	mile per hour	mph		mph		1.0 mph (1.6 km/h)	mph km/h mph kn
	foot per second	ft/s (foot/s)		ft/s	long code "foot/s" outputs foot per second (and never feet)	1.0 ft/s (0.30 m/s)	ft/s m/s
Maritime units	knot	kn (knot)		kn		1.0 kn (1.9 km/h; 1.2 mph)	kn mph

Temperature

Temperature
(Full list)

system	unit	unit- code		symbol	notes	sample default conversion	combination output units
SI	K	K		K	Allows triple output units. See: full list.	1.0 K (−272.15 °C; −457.87 °F)	K °C (K C) K °R (K R) K °F (K F)
	°C	°C (C)		°C		1.0 °C (33.8 °F)	°C K (C K) °C °R (C R) °C °F (C F)
Imperial & US customary	°R	°R (R)		°R		1.0 °R (0.556 K; −458.670 °F; −272.594 °C)	°R K (R K) °R °C (R C) °R °F (R F)
	°F	°F (F)		°F		1.0 °F (−17.2 °C)	°F K (F K) °F °C (F C) °F °R (F R)
	Celsius change	C-change			Used for temperature intervals instead of actual temperatures Example:  {{convert|5|C-change|0}} warmer Result: 5 °C (9 °F) warmer
	Fahrenheit change	F-change			Used for temperature intervals instead of actual temperatures Example:  {{convert|10|F-change|0}} colder Result: 10 °F (6 °C) colder

Torque

Torque
(Full list)

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
Industrial
SI	newton-metre	Nm		N⋅m	Triple combinations are also possible. See the full list.	1.0 N⋅m (0.74 lbf⋅ft)	Nm kg.m Nm lb.ft
Non-SI metric	kilogram metre	kg.m		kg⋅m		1.0 kg⋅m (9.8 N⋅m; 7.2 lb⋅ft)	kg.m Nm kg.m lb.ft
Imperial & US customary	pound force-foot	lb.ft		lb⋅ft		1.0 lb⋅ft (1.4 N⋅m)	lb.ft Nm lb.ft kg-m
Scientific
SI	newton-metre	N.m		N⋅m	Triple combinations are also possible. See the full list.	1.0 N⋅m (0.74 lbf⋅ft)	N.m kgf.m N.m lbf.ft
Non-SI metric	kilogram force-metre	kgf.m		kgf⋅m		1.0 kgf⋅m (9.8 N⋅m; 7.2 lbf⋅ft)	kgf.m N.m kgf.m lbf.ft
Imperial & US customary	pound force-foot	lbf.ft		lbf⋅ft		1.0 lbf⋅ft (1.4 N⋅m)	lbf.ft N.m lbf.ft kgf.m

Volume

Volume
(Full list)

system	unit	unit- code		symbol or abbrev.	notes	sample default conversion	combination output units
SI	cubic metre	m3		m3	US spelling: cubic meter one kilolitre	1.0 m3 (35 cu ft)
	cubic centimetre	cm3		cm3	US spelling: cubic centimeter one millilitre	1.0 cm3 (0.061 cu in)
		cc		cc
	cubic millimetre	mm3		mm3	US spelling: cubic millimeter	1.0 mm3 (6.1×10−5 cu in)
non-SI metric	kilolitre	kl		kl	US spelling: kiloliter one cubic metre	1.0 kl (35 cu ft)
		kL		kL
	litre	l		L	US spelling: liter one cubic decimetre Allows triple output units. See: full list.	1.0 L (0.22 imp gal; 0.26 US gal)	l impgal l USgal l U.S.gal l USdrygal l U.S.drygal
		L		L			L impgal L impqt L USgal L U.S.gal L USdrygal L U.S.drygal
	centilitre	cl		cl	US spelling: centiliter	1.0 cl (0.35 imp fl oz; 0.34 US fl oz)
		cL		cL
	millilitre	ml		ml	US spelling: milliliter one cubic centimetre	1.0 ml (0.035 imp fl oz; 0.034 US fl oz)	ml impoz ml USoz ml U.S.oz
		mL		mL			mL impoz mL USoz mL U.S.oz
Imperial & US customary	cubic yard	cuyd		cu yd		1.0 cu yd (0.76 m3)
	cubic foot	cuft (cufoot)		cu ft	long code "cufoot" outputs cubic foot (and never feet)	1.0 cu ft (0.028 m3)
	cubic inch	cuin		cu in		1.0 cu in (16 cm3)
Imperial	imperial barrel	impbbl		imp bbl	36 imp gal	1.0 imp bbl (160 L; 36 imp gal; 43 US gal)
	imperial bushel	impbsh		imp bsh	8 imp gal	1.0 imp bsh (36 L; 8.0 imp gal; 8.3 US dry gal)
		impbu		imp bu
	imperial gallon	impgal		imp gal	4.54609 litres by definition, also 4 imp qt or 8 imp pt or 160 imp fl oz Allows triple output units. See: full list.	1.0 imp gal (4.5 L; 1.2 US gal)	impgal l impgal L impgal USgal impgal U.S.gal impgal USdrygal impgal U.S.drygal
	imperial quart	impqt		imp qt	1/4 imp gal or 40 imp fl oz	1.0 imp qt (1,100 ml; 38 US fl oz)
	imperial pint	imppt		imp pt	1/8 imp gal or 20 imp fl oz	1.0 imp pt (0.57 L)
	imperial fluid ounce	impoz (impfloz)		imp fl oz	1/160 imp gal	1.0 imp fl oz (28 ml; 0.96 US fl oz)	impoz USoz impoz U.S.oz impoz ml impoz mL
US customary liquid measure	US barrel	USbbl		US bbl	31½ US gal used for liquids except for oil and beer (see the full list)	1.0 US bbl (120 L; 32 US gal; 26 imp gal)
		U.S.bbl		U.S. bbl
	barrel	oilbbl		bbl	42 US gal	1.0 bbl (0.16 m3)
	US beer barrel	USbeerbbl (usbeerbbl)		US bbl		1.0 US bbl (120 L; 31 US gal; 26 imp gal)
		U.S.beerbbl (usbeerbbl)		U.S. bbl
	US gallon	USgal		US gal	231 cubic inches by definition, also 4 US qt or 8 US pt or 128 US fl oz Allows triple output units. See: full list.	1.0 US gal (3.8 L; 0.83 imp gal)	USgal l USgal L USgal impgal
		U.S.gal		U.S. gal			USgal l USgal L USgal impgal
	US quart	USqt		US qt	1/4 US gal or 32 US fl oz	1.0 US qt (950 ml)
		U.S.qt		U.S. qt
	US pint	USpt		US pt	1/8 US gal or 16 US fl oz	1.0 US pt (0.47 L; 0.83 imp pt)
		U.S.pt		U.S. pt
	US fluid ounce	USoz (USfloz)		US fl oz	1/128 US gal	1.0 US fl oz (30 ml)	USoz ml USoz mL USoz impoz
		U.S.oz (U.S.floz)		U.S. fl oz			U.S.oz ml U.S.oz mL U.S.oz impoz
US customary dry measure	US dry barrel	USdrybbl		US dry bbl	105/32 US bsh	1.0 US dry bbl (0.12 m3)
		U.S.drybbl		U.S. dry bbl
	US bushel	USbsh		US bsh	2150.42 cubic inches by definition	1.0 US bsh (35 L; 8.0 US dry gal; 7.8 imp gal)
		U.S.bsh		U.S. bsh
	US bushel	USbu		US bu	2150.42 cubic inches by definition	1.0 US bu (35 L; 8.0 US dry gal; 7.8 imp gal)
		U.S.bu		U.S. bu
	US dry gallon	USdrygal		US dry gal	1/8 US bsh Allows triple output units. See: full list.	1.0 US dry gal (4.4 L)	USdrygal l USdrygal L USdrygal impgal
		U.S.drygal		U.S. dry gal			U.S.drygal l U.S.drygal L U.S.drygal impgal
	US dry quart	USdryqt		US dry qt	1/32 US bsh	1.0 US dry qt (1,100 ml)
		U.S.dryqt		U.S. dry qt
	US dry pint	USdrypt		US dry pt	1/32 US bsh	1.0 US dry pt (550 ml)
		U.S.drypt		U.S. dry pt

Extra

Pressure
(Full list)

	unit	unit- code		symbol or abbrev.		sample default conversion
	gigapascal	GPa		GPa		1.0 GPa (150,000 psi)
	megapascal	MPa		MPa		1.0 MPa (150 psi)
	kilopascal	kPa		kPa		1.0 kPa (0.15 psi)
	hectopascal	hPa		hPa		1.0 hPa (0.015 psi)
	pascal	Pa		Pa		1.0 Pa (0.00015 psi)
	millipascal	mPa		mPa		1.0 mPa (1.5×10−7 psi)
	millibar	mbar		mbar		1.0 mbar (1.0 hPa)
		mb		mb
	decibar	dbar		dbar		1.0 dbar (10 kPa)
	bar	bar		(none)		1.0 bar (100 kPa)
	kilobarye	kBa		kBa		1.0 kBa (1.0 hPa)
	barye	Ba		Ba		1.0 Ba (0.10 Pa)
	standard atmosphere	atm		atm		1.0 atm (100 kPa)
	torr	Torr		Torr		1.0 Torr (0.13 kPa)
	millimetre of mercury	mmHg		mmHg		1.0 mmHg (0.13 kPa)
	inch of mercury	inHg		inHg		1.0 inHg (3.4 kPa)
	pound per square inch	psi		psi		1.0 psi (6.9 kPa)

Fuel efficiency

Fuel efficiency

	unit	unit- code			notes		combinations
	kilometres per litre	km/l (km/L)			Use km/L to get "km/L"		km/l mpgimp km/l mpgus
	litres per 100 kilometres	l/100 km (L/100 km)			Use L/100 km to get "L/100 km"		l/100 km mpgimp l/100 km mpgus
	litres per kilometre	l/km (L/km)			Use L/km to get "L/km"		l/km impgal/mi l/km usgal/mi
	miles per imperial gallon	mpgimp					mpgimp mpgus
	miles per US gallon	mpgus (mpgUS, mpgU.S.)			Use mpgUS to get "US" Use mpgU.S. to get "U.S." mpgus will give "U.S." if spelling is set to US & "US" otherwise		mpgus mpgimp
	imperial gallons per mile	impgal/mi					impgal/mi
	US gallons per mile	usgal/mi (USgal/mi, U.S.gal/mi)			As above with the us vs US vs U.S.		usgal/mi
The mpgUS, mpgU.S., USgal/mi vs U.S.gal/mi, km/L, L/100 km and L/km variants work within combinations also (making 36 combinations in total).

Population density

Population density

	unit	unit- code			notes		combinations
	inhabitants per square kilometre	PD/km2			PD stands for population density, i.e. humans (inhabitants)		PD/km2 PD/sqmi
	per square kilometre	/km2			Used when the word 'inhabitants' would be inappropriate.		/km2 /sqmi
	inhabitants per hectare	PD/ha					PD/ha PD/acre
	per hectare	/ha					/ha /acre
	inhabitants per square mile	PD/sqmi			PD stands for population density, i.e. humans (inhabitants)		PD/sqmi PD/km2
	per square mile	/sqmi			Used when the word 'inhabitants' would be inappropriate.		/sqmi /km2
	inhabitants per acre	PD/acre					PD/acre PD/ha
	per acre	/acre					/acre /ha

Cost per unit mass

Cost per unit mass

	unit	unit- code			notes		combinations
	dollars per pound	$/lb			"$" can mean US$, HK$, etc.		(none)
	dollars per kilogram	$/kg					(none)
	dollars per troy ounce	$/ozt			12 troy ounces in 1 troy pound		(none)

The hat letter

The hat letter, or Why some ideas fail to make it into the out tray. I remember reading something like this a very long time ago, in a book by someone like James Thurber or Stephen Leacock or Leo Rosten. Re-constructed from memory, with a few extra invented phrases. Anyone recognise it, or something like?

Messrs. Sue, Grabbitt & Runne,

127 Lincoln's Inn,

London WC2

Date as postmark

Dear Sirs,

re: Final Demand for Payment, your ref. 192/1828/4B-673

Thank you for your letter of the 2nd inst.

You are evidently unaware of the method we use for paying our bills.

At the end of every month we receive a statement from our bank, telling us how much money we have. We then write the names of each of our creditors and the amount due them on a slip of paper, and place all the slips in a hat. Next - averting our gaze in order to encourage an expectant sense of the random - we pull one slip at a time out of the hat, write out a cheque for the full amount to the creditor, seal it in a stamped addressed envelope and put in the letter tray. We continue to repeat this simple exercise until there is no more money left. At the end of the following month, we write the names of our remaining creditors on slips of paper … and so it goes.

We therefore beg to inform you that if you persist in sending us any further letters, your name will not even go in the damn hat.

Faithfully yours,

pp Acme Manual Co., Inc.