Abbreviations in Science and Technology

By Mark Nichol

Because of the bewildering variety of abbreviations for scientific and technological terms and the inconsistency of treatment, writers and editors are advised to consult with publications like The Chicago Manual of Style or a handbook specific to a scientific discipline or to an industry to confirm standard modes of abbreviation for specific terms. This post provides an assortment of examples that demonstrate the seemingly chaotic nature of scientific and technological abbreviation.

Abbreviations for scientific and technological terms generally do not use periods; an exception is physical dimensions for nonmetric quantities such as gr. for grain, qt. for quart, and bbl. for barrel and temporal abbreviations such as sec. (second), hr. (hour), and mo. (month). Note, too, that unlike abbreviations for physical dimensions, those for durations of time include an s when they are plural: “15 mins.,” “5 yrs.,” etc.).

Abbreviations of metric units are almost invariably lowercased; an exception is mL for milliliter, so that a lowercase l is not confused for the numeral 1. The format of abbreviation of US units of measure is inconsistent. Sometimes, abbreviations may consist of the first two letters of a word (for example, mi. for mile); in other cases, the abbreviation may be formed from the first and last letters (as in yd. for yard). Rarely, an abbreviation of a foreign term is used, as with lb. instead of po. or pd. for pound, while the abbreviation oz. for ounce is based on the medieval Italian form onza.

Just as these abbreviations are usually appropriate only for charts and tables, not for what is called running text (the prevailing content in a publication distinct from display copy—headlines, captions, and the like—and graphic elements such as charts and tables), symbols are usually avoided in running text, but the percentage symbol (%) is occasionally used there, especially in statistically dense content, as are symbols for minutes and seconds in time or distance. However, these should be style as primes (′) and double primes (″), although some publications use straight, or dumb, quotation marks (‘ or “) or even curly, or smart, ones (’ or ”).

Capitalization of scientific and technological terms is variable, sometimes even for terms in the same category. Just as the first letter for the abbreviation of tablespoon is capitalized to distinguish Tbsp. from the abbreviation for teaspoon (tsp.), Bps (for “bytes per second”) and bps (for “bits per second”) are distinguished by initial capitalization of the former but not the latter, and abbreviation of megabit and megabyte are distinguished as Mb and MB, though kilobit is abbreviated kb, while kilobyte is shortened to KB (or simply K). The first letter of the abbreviations for “kilobyte per second” (Kbps) and “megabyte per second” (Mbps) is also capitalized.

Abbreviations of scientific units named for scientists have initial capitalization, though the spelled-out terms themselves are lowercased—for example, Bq (becquerel), Da (dalton), and J (joule). This is true of abbreviations of words based on surnames, such as F for farad (an abbreviation of Faraday) and V for volt (from Volta). And because the -bel in decibel is in honor of Alexander Graham Bell, that segment of the word for a unit of measurement of sound is capitalized in abbreviation to dB. Likewise, the first letter in Btu is capitalized because it stands for British. (The other letters stand for thermal and units.)

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7 Responses to “Abbreviations in Science and Technology”

  • Dale A. Wood

    There are many reasons why the “K” prefix for “kilo” in the S.I. should always be capitalized:
    1). It is specified that way in the documents for the S.I., and
    2). The lower-case “k” is Boltzmann’s constant in physics.
    Thus just as ApK wrote: Kbps = kilobits per second, and KBps = kilobytes per second. Confusing matters are that as for units, “K” = kelvins, and K is the chemical symbol for potassium. This comes from the German word “Kalium” = potassium.
    There is also “Na” for “Natrium”, where Natrium = sodium.
    Thus we get chemical compounds like KOH and NaCl.
    D.A.W.

  • Dale A. Wood

    Venqax made a small typographical error in his first sentence, and what he meant was “G before an E, or a I, or a Y is soft,” in English. These covers thousand of cases like gel, gem, gene, genie, genius, Gentile, germ;
    gigantic, gin, Ginnie Heinlein, whose real first name was Virginia, giraffe, gist;
    gymnasium (gym), gypsum, Gypsy, gyre, gyrocompass, gyrocopter, gyroscope.
    Exceptions are found in gecko, GEICO, get, finger, giddy, gig, gigohm, gill, girth, Giza, gynecology, gigawatt (!)….
    As for English vs. German pronunciations, there are words that are spelled the same in both languages and mean the same but pronounced differently, notably “General” and “Finger”.
    “General” in German has a “hard G”, so it does not sound like “Genie”. Also in German, “Genie” means “genius”, so is the General a genius or a lunatic? (That was sometimes asked about Stonewall Jackson, General Sherman, General Patton, General LeMay of SAC,…)
    The difference in “Finger” is how it divides into syllables:
    fin/ger vs. Fing/er. In either case, the “g” does not sound like a “j”.
    In Latin, “Imperator” means “general” and not “emperor”. There is a sentence that begins, “Caesare Imperator…” that says, “If Caesar is the general, then the Romans cannot lose…”
    D.A.W.

  • venqax

    “G before an I or and I or a Y is soft, which In English means the affricate /dʒ/,” pronounced J-like, s pretty much the rule in the English language. The only real exception is a few early or old words originating in Germanic languages (even that is Jermanic), so girl, give, gift. But giga is not such a one. Just like its relative giant– which is not pronounced guy-ant, either. But, ignorance of these things being what it is, I don’t doubt you’ve never heard pronounced the J-way, even by those who should know better– as does Doc Brown, a literatescientific Jenius.

  • Agua Caliente

    I thought the Kbps vs. kbps was worth additional reading, so I did just that. I found a mish-mash of guidelines and opinions about which letter should be capped and under what circumstances. One source say Kbps is bits; another says it’s bytes, and so on. Let’s call the whole thing off, shall we? Perhaps I will consider k-bytes or k-bits in some circumstances…for example, “k-bytes/sec.” More likely, though, I’ll just stick with kbps and hope that the context makes it clear.

  • Agua Caliente

    Having been in tech for a while, I cannot recall having heard giga-anything pronounced with the j-sound. Exception: Back To The Future’s “jigawatts.” Whether that is an indicator of what’s correct or truly comprehensive, I really can’t say, but that’s my empirical take on it.

    Kbps OR kbps might both be parsed as kilobytes, although given a technical audience, it could also flip to bits, depending on context.

  • venqax

    Ugh. I’m not a technology person a’tall. So, there being no rules apparently, and lacking much familiarity with these I guess I’d just have to look up each and every one every time. One more reason not to like technology much. I DO know giga– should be pronounced Jiga. So there! Take that technolog ggy (keyboard’s stuck)

  • ApK

    Wow. Confusing. In my experience as a technologist, for data transfer rates, M and K have always been capitalized, and lowercase b is for bits, uppercase B is for bytes. Kbps would be kilobits per second, and KBps would be Kilobytes per second. It’s by no means entirely consistent, as programmers are not known for their skill at documentation (or English), but that is by far the most common usage I’ve encountered in the wild.

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