Elements of Bile

Metric illustration from 1877. Note the capital K.

By The Metric Maven

When I first attended University, my English instructor became concerned about my competence with the language. She insisted that my writing was so riddled with problems that I must be tested for a learning disability. I sat for about eight hours of testing. The next week I returned to have my results analyzed. The woman looked at me with an almost relieved countenance and said “oh, your problem was easy to identify, you spell logically instead of correctly and generally use a single letter in place of redundant ones when spelling, you don’t see any rhyme or reason in why capitalization occurs so you only do it at the beginning of sentences, and  you see many grammatical rules as arbitrary and inconsistent, and so you do not follow them. We can fix this!”

I have done what I can to conform to the requirements of “standard” English over the years, but I have more regard for what appears to be rational usage than “proper” usage. Longtime readers know that I have a real problem with using a small k for kilo. The ordinary frequencies of radios waves are described as Hz (hertz), kHz (kilohertz), MHz (megahertz), GHz (gigahertz), THz (terahertz) and upward. All the metric prefixes for magnification in this series are capitalized—except for?—kilohertz. Longtime readers also know that I would do away with the prefix cluster around unity, and only use them for historical reference as atavistic prefixes. No more deca or hecto in the case of magnifying units. This would make the kilo prefix k, the only one which is not capitalized for the magnifying prefixes. I would then use capital K so that all the magnifying prefixes are consistent, and their capitalization would be a clue that they are magnifying prefixes. The frequencies I cited would then become KHz, MHz, GHz and THz. Distances would become Km, Mm, Gm and Tm. We would have Kg, Km and KL for kilogram, kilometer and kiloliter respectively.

Shinkansen (Osaka–Tokyo) Bullet Train Speedometer ~ 1964
Shinkasen (Osaka-Tokyo) Bullet Train Speedometer ~ 1964

Incidentally, I recently gave a lecture to a chemistry class at a local all girls high school and mentioned that small k was the accepted symbol for kilo, but I would make it a capital k. The teacher approached me after the lecture and indicated that it was her understanding that capital K is the recognized prefix for kilo. “Where did you get that idea?” I asked. She opened the chemistry textbook used for the class and in the first section it had all the metric prefixes listed, and to my amazement, the K for kilo was capitalized. I was dumfounded and stared for a moment in disbelief. It was clear to me that a capital K is so logical, that it had somehow made its way into a high school chemistry textbook. Recently I also saw a PBS documentary about a famous train crash in Japan. The documentary had historical footage from 1964 of Japan’s early bullet trains and for a moment the speedometer of a train was shown. It had Km/h with a capital k (or should it be capital K?). It was clear to me that many peoples minds automatically attempt to make the metric prefixes logically consistent, independent of “accepted usage.”

I’m sure there are plenty of reactionary minds which would object to a capital K for the metric prefix kilo on the basis that it would be confused with Kelvin. I’ve made it plain in  a previous blog that I believe the practice of naming units after scientists never should have occurred. There are also those who point out that the kilogram is a base unit (one must admit its an odd base unit that has a prefix.) and we must for some reason be reminded of this by using a lower case k—for mass and all other uses!–km, kL, kHz, and so on.  This assertion is nothing but a goldfish bowl filled with red herrings. Rational consistency in engineering and science takes precedence over “heritage.”—or as the English might say “heritage”.

In my usage, all the magnifying prefixes would be upper case, K, M, G, T, P, E, Z, Y and all the reducing prefixes would be lower case m, µ, n, p, f, a, z, y. This would produce an “element of style” which would be consistent with technical usage. All metric prefixes would differ by 1000, the upper case would magnify and the lower case would reduce the base unit. Could we all just agree on the gram as a “heritage virtual base unit?” This proposed usage would be a consistent expression that any grade school student could master in a day and use for the rest of their life. It would be a consistent rule for the literary expression of metric prefixes that one could count on, unlike “i before e except after c and in words like neighbor and weigh.” And weight of course.

Longtime readers have heard this all before, but what I’m proposing in this essay goes far beyond capitalizing K when using the kilo prefix. I have my own ideas about the capitalization of their accompanying words. I would capitalize Kilohertz, Kilogram, Kilometer and all the words which use a magnifying metric prefix. In general, if a word is describing a metric prefix-unit combination, and the prefix magnifies, then it should be capitalized, and if it reduces, then it should be lower case. For example Petagrams would be Pg, and mg would be milligrams. In astronomy Km would be Kilometers, Mm is Megameters, Gm is Gigameters and so on. All the names would be capitalized. If one is working with electronics, mm is millimeters, µm is micrometers, nm is nanometers and so on.

The only barrier between myself and this usage is the “keepers of style manuals.” They will complain about my use of KHz, but not object to  a sentence which states “the weight of a piano is many kilograms” which is a fundamentally flawed statement. If it were written “the weight of a piano is many Kilograms” I’m sure there would be guffaws and outbursts about the capital K. It would probably be lost on them that grams are mass and newtons are metric “weight” which is a much larger problem.

I’m going to institute this style practice in my blog, and fully expect there will be some wagging of bony fingers, and venting. My only defense will be to state that I have developed my own consistent style manual, which is named for what it might generate by its usage, The Elements of Bile.


If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page and contribute. Also purchase his books about the metric system:

The first book is titled: Our Crumbling Invisible Infrastructure. It is a succinct set of essays  that explain why the absence of the metric system in the US is detrimental to our personal heath and our economy. These essays are separately available for free on my website,  but the book has them all in one place in print. The book may be purchased from Amazon here.


The second book is titled The Dimensions of the Cosmos. It takes the metric prefixes from yotta to Yocto and uses each metric prefix to describe a metric world. The book has a considerable number of color images to compliment the prose. It has been receiving good reviews. I think would be a great reference for US science teachers. It has a considerable number of scientific factoids and anecdotes that I believe would be of considerable educational use. It is available from Amazon here.


The third book is called Death By A Thousand Cuts, A Secret History of the Metric System in The United States. This monograph explains how we have been unable to legally deal with weights and measures in the United States from George Washington, to our current day. This book is also available on Amazon here.

12 thoughts on “Elements of Bile

  1. Well, the real barrier is the “Keepers of the SI,” the BIPM. If you convince them, I’ll do it; if you don’t, I won’t. I rather doubt that offering a counter-SI really facilitates metrication in the United States.

    If we all implement the SI however we want, it will be Customary 2.0 with new units.

    The SI Brochure either expressly allows ( l or L as symbol for liter) or at least acknowledges (eg, US spelling of meter, liter) certain minor variations. Greater variation than that should be STRONGLY discouraged.
    [wags bony finger]

  2. Well, SI, in its implementation – also in long ago metricated (but often still quite illiterate from the measurements point of view) countries – sadly is still quite and almost only “metrically customary”, as it is incredibly never used in its full power, but only for a very limited subset of its real potential – let’s say, banally, only from millimeters to kilometers, in everyday life (which might be the most important aspect, after all: most people’s life…).

    A capitalized K for Kilo would certainly be more coherent, at least as far as possible, inside an anyway still quite “chaotic” historical SI, probably in desperate need of some post-modern rationalizing, at least in order to make it more future-ready, if not more appealing to everyone.

    Possible obstacles against a more rational, and of course also really worldwide SI…? Bureaucracy (mostly self-referential and also arrogant), first of all – which could certainly be quite detrimental for the future of SI (and for the planet in general!).

    A better option would probably be to “decentralize” SI – and not only…- and thus make it a truly open source-like project, constantly revised and renewed, as society evolves: but that would of course also require a more evolved and self-conscious society; or, as in some software projects, even go as far as to fork the SI – but that wouldn’t certainly be good, for something that anyway must be a common and shared industry standard, across the world.

    Rather wishful thinkings, anyway, at the current state of things, sadly…

  3. You’re just being ridiculous now. Capitalisation rules for English are fairly clear: the beginning of a sentence and proper nouns. Prefixed units are not proper nouns. Not only that, but no unit name should begin with a capital letter, with only a slightly weird way of writing “degrees Celsius”.

    That is the case whether you’re talking about newtons, joules, watts, volts, and any other unit named after a person. The unit name, with or without prefixes, should not begin with a capital letter if it’s not the beginning of a sentence.

    They’re just regular nouns. When they aren’t the beginning of a sentence, they shouldn’t have a capital letter. You’re just introducing your own inconsistency because you feel like adhering to *your own* “standard”. Yet, the point of a common standard is that you don’t get to make up your own rules.

    Yes, sometimes legacy sucks. Sometimes hindsight reveals that past decisions weren’t always the best. But, at the time kilo- was first used as a unit prefix, prefixes for mega- and beyond didn’t exist and no prefix had an uppercase symbol.

    I know I’ve told you this before, and I know you’re just going to be extremely stubborn about this. But I just hope other people reading this realise that you’re wrong and don’t follow your lead.

    • You misunderstand the issue: Mm is not an abbreviation, it is a symbol. As such, it has a completely separate and distinct meaning from mm. One must always capitalize Mm, never capitalize mm, else the meaning gets switched! As such, Km makes more consistent sense, but km follows the rules of the Keepers of SI. In neither case does your grammar pedantry apply at all.

      • I wasn’t talking about the symbols at all. I was talking about the names, and specifically addressing the Metric Maven’s ridiculous assertion that unit names should be written like “Kilograms” because they start with a multiplicative prefix.

        Regarding the symbols, however, he’s just absolutely wrong. They are indeed case sensitive, and disagreeing with the standard is not a valid reason to capitalise the symbol for kilo-.

  4. The Maven’s desire to see the letter for kilo- become uppercased is something I could agree with but, as others have indicated above, uppercasing words such as “kilogram” is, to say the least, somewhat silly.

    With respect to the Maven’s desire to eliminate the prefixes that “cluster” around unity, namely hecto-, deca-, deci-, and centi-, such is understandable because he wants only “prefixes [that] differ by [a multiple of] 1000”.

    Although I can commiserate with this, it would be inconvenient to do so completely, and so a better position to take would be to classify these four MMPs [for Maverick Maven Prefixes] as simply “informal” and perhaps for such use. For example, for many years we’ve seen things like “95 mg/100 mL” but now it is almost always “95 mg/dL”, which is easier to digest at a glance.

    Also, what about the not uncommon (except in the U.S.) unit of area, the hectare (ha)? Why should we not know it is a square hectometer, or (100 hm)^2 = 10 000 m^2, and so 100 ha = 1 km^2?

    Related to this was an interesting full-page “Paid Post” on Page A19 of yesterday’s [10 Dec 2014] NYTimes titled “How Much Energy Will Tomorrow’s Megacities Need?”, which was supported by Shell, and concluded with a graph titled “Urban Density And Transportation-Related Energy Consumption”, with the graph showing cities in a plot of “Urban Density (Inhabitants Per Hectare”)” vs “Transport-Related Energy Consumption (Megajoules Per Year)”. Ah! — and Aha! — something all of us in the Maven’s Forum should appreciate!

    • Correction to my posting here: ““prefixes [that] differ by [a multiple of] 1000″ should read “prefixes [that] differ by [a power] of 1000”, or, better yet, “prefixes that represent of a power of 1000” (that is, 10^(3n), where n is an integer).

  5. Something we could probably all more or less agree on could perhaps be: uppercase K for the kilo- prefix, thus making it coherent with the other magnifying prefixes; lowercase for the name, e.g. kilogram; and thus (if the deca- and hecto- prefixes are not deprecated and maintained, even in an informal way), for coherence, also D instead of da for deca and H instead of h for hecto.

    All this (completely coherent prefixes) would probably also help to supersede the “customary” metric use in everyday life, which tends to be favored also because of the different, lowercase prefixes up to the thousands (as if it were a privileged zone); instead, if all prefixes follow the same rule, it’s probably also easier to see them as only a part of a wider possible use of SI prefixes, also in everyday life (e.g. megameters, and so on).

    But does the BIPM – and others – even contemplate change and evolution of the SI, today? That’s the question, probably (also applicable to all bureaucratic institutions, in general: after some time, they tend to be rather self-referential, thus making substantial evolutions difficult, if not impossible, without a change of context).

    A measurement system born from a revolution cannot remain static, anyway: it must evolve with times…

  6. Well, the dual symbols, either l or L, were approved for the liter in 1979 by the 16th CPGM. They “encouraged” the CIPM to make a recommendation on just one by the 18th CGPM (1987) but in 1990 the CIPM reported it was “too soon” and the matter has never been brought up again. Thirty-five years on, it is still too soon as they just met and it wasn’t a topic. Some people still use the script l (ℓ) which is deprecated. I see little hope for capitalized symbols for deka, hecto, and kilo.

    • As John probably is aware, probably the only reason why the symbol for liter went from l to L was because in the days of typewriter, a lowercase l looked too much like a 1, which could be seen here is no longer the case. But now as I [sic!] type this, there is a too-close resemblance to an uppercase i.

      Let’s see: Type “1 liter” both ways, symbolically: 1 L and 1 l. Although both are fairly clear, that uppercase-like I (as in me) in the latter makes the change to uppercase L something we should keep.

      So, which of the following are two uppercase i’s?: ll or lI or Il or II

      • The US prefers L in all instances (with or without prefix). Per Wikipedia, Australia and Canada are the other big users of L. Some countries use L alone and l with prefixes, but most just use l.

        Since L was introduced to avoid confusion of l, those of us who adopted it aren’t going back. It is not clear to me why those who cling to l do so.

        However, it also seems to me that the BIPM could decide between dalton (Da) and unified atomic mass unit (u) which are synonyms. I vote dalton.

        • And I vote yoctogram! That is, redo the Periodic Table in yoctograms!!

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