There are standard prefixes for units in the SI international system of units. Some of these, such as micro, nano or giga are relatively common in everyday language, whereas others are only known to scientists and engineers. I wondered how frequently the different prefixes appear in company names, and how registered they are as domain names.
Introduction to Prefixes
The tables below give the standard prefixes in the first column. The first table covers units that multiply by a factor, such as a megawatt means one million watts of electrical power, while the second covers units that are some fraction, such as a milligram means one thousandth of a gram.
There are standard abbreviations for each prefix, such k for kilo or n for nano. Note that capitalization matters, with MW meaning megawatt while mW would be milliwatt. Only one relatively unused prefix, deca, uses a 2-letter abbreviation. There is only one prefix, micro, that uses a Greek letter for its abbreviation.
In the column marked Meaning is the power of ten for each prefix, while the Term column gives the associated name. For example, mega is 10 to the power 6, meaning 10*10*10*10*10*10=1,000,000, or million. The second half of the table correspond to negative exponents, meaning one over that factor. For example, milli is 10 to the power of -3, which equals 1/(10*10*10)=1/1000 ore one-thousandth.
The official list of prefixes is expanded from time to time. For example, in 2022 ronna, quetta, ronto and quecto were added.
Good references are NIST Metric SI Prefixes Site and Metric Prefixes.
Most Highly Registered as Domain Names
All of the prefix terms are registered in many extensions, the values given in the TLDs (Top Level Domains) column in the tables. The most registered is mega (533), followed by nano (460), micro (406), and giga (365). The least registered, the relatively new prefix quecto, is still taken in 27 extensions, including all of the popular ones.
I also used dotDB to look at the total domain count for each prefix. The highest was exa with 539,497, but keep in mind this includes all words that begin with ‘exa’, such as ‘exact’. Others with domain counts above 100,000 are tera, mega, micro, deca, and atto, with nano at more than 98,000.
Use In Business Names
The Active OCs column gives the number of listings for that term in business names, including also known as or formerly known as names. The data is from OpenCorporates, and I only included active listings.
Here are my observations from the data:
I used NameBio to look at sales of the various prefix terms, only looking at sales of $1000 or more in order to concentrate on retail. One has to be careful in searches, since most of the terms appear in sales of words with no relationship to the prefix meaning. For example, if you just the Contains setting on NameBio, and search for ‘deci’ the majority of the sales will be of words like ‘decision’. For this reason, I restricted my searches to the NameBio As A Prefix setting, since it would make sense that the SI unit prefixes would most find use as a prefix.
The number of $1000 plus sales listed in NameBio with the term used as a prefix is given in the rightmost column of my table. Here are some observations:
I was not sure what I would find when I began this analysis. While a few terms like mega, micro, nano and giga do relatively well by the measures, I don’t think in most cases it it is strongly related to the fact that the terms are official unit prefixes.
The standard prefixes are largely derived from Latin or Greek terms, and the branding use is no doubt related, as brand names sometimes build on meanings in Latin, Italian or another language.
Updates:
Mar. 27, 2025 'millionth' corrected to 'thousandth' in one place.
Thanks to dotDB, OpenCorporates and NameBio.
Introduction to Prefixes
The tables below give the standard prefixes in the first column. The first table covers units that multiply by a factor, such as a megawatt means one million watts of electrical power, while the second covers units that are some fraction, such as a milligram means one thousandth of a gram.
Official unit prefix names, giving symbol, meaning, and word describing the factor. This is followed by number of registered extensions (TLDs) and total number of registered domain names (Domain Count). That information is via dotDB. Active OCs gives the number of business names that include that term, with data from OpenCorporates. The final column shows the number of NameBio listed sales with that term as a prefix, only including sales of $1000 plus.This table includes prefixes that multiply by a factor.
There are standard abbreviations for each prefix, such k for kilo or n for nano. Note that capitalization matters, with MW meaning megawatt while mW would be milliwatt. Only one relatively unused prefix, deca, uses a 2-letter abbreviation. There is only one prefix, micro, that uses a Greek letter for its abbreviation.
This table has prefixes that divide by a factor. Official unit prefix names, abbreviations, meaning, and word describing the factor. This is followed by number of registered extensions (TLDs) and total number of registered domain names (Domain Count). That information is via dotDB. Active OCs gives the number of business names that include that term, with data from OpenCorporates. The final column shows the number of NameBio listed sales with that term as a prefix, only including sales of $1000 plus.
In the column marked Meaning is the power of ten for each prefix, while the Term column gives the associated name. For example, mega is 10 to the power 6, meaning 10*10*10*10*10*10=1,000,000, or million. The second half of the table correspond to negative exponents, meaning one over that factor. For example, milli is 10 to the power of -3, which equals 1/(10*10*10)=1/1000 ore one-thousandth.
The official list of prefixes is expanded from time to time. For example, in 2022 ronna, quetta, ronto and quecto were added.
Good references are NIST Metric SI Prefixes Site and Metric Prefixes.
Most Highly Registered as Domain Names
All of the prefix terms are registered in many extensions, the values given in the TLDs (Top Level Domains) column in the tables. The most registered is mega (533), followed by nano (460), micro (406), and giga (365). The least registered, the relatively new prefix quecto, is still taken in 27 extensions, including all of the popular ones.
I also used dotDB to look at the total domain count for each prefix. The highest was exa with 539,497, but keep in mind this includes all words that begin with ‘exa’, such as ‘exact’. Others with domain counts above 100,000 are tera, mega, micro, deca, and atto, with nano at more than 98,000.
Use In Business Names
The Active OCs column gives the number of listings for that term in business names, including also known as or formerly known as names. The data is from OpenCorporates, and I only included active listings.
Here are my observations from the data:
- By far the most popular in terms of business name use are mega and micro, both with more than 20,000 business listings.
- Most of the business names seem to be multipart, e.g. mega + another term like MegaDeals.
- Nano, pico, tera and giga are also widely used with 1750 or more active business name listings.
- Probably nano is more used in a sense linked to nanoscale technology than is the case for any other prefix, although even for it most uses appear unrelated or loosely related.
- Except for quecto, there are at least 40 business listings for all of the other terms, with many having hundreds.
I used NameBio to look at sales of the various prefix terms, only looking at sales of $1000 or more in order to concentrate on retail. One has to be careful in searches, since most of the terms appear in sales of words with no relationship to the prefix meaning. For example, if you just the Contains setting on NameBio, and search for ‘deci’ the majority of the sales will be of words like ‘decision’. For this reason, I restricted my searches to the NameBio As A Prefix setting, since it would make sense that the SI unit prefixes would most find use as a prefix.
The number of $1000 plus sales listed in NameBio with the term used as a prefix is given in the rightmost column of my table. Here are some observations:
- Mega is a highly-sold term, with 174 sales on NameBio at $1000 or more, including 8 above $10,000 and one above $100,000. Almost all sales use ‘mega’ meaning very large, rather than in a specific prefix multiple meaning.
- Use of micro as a leading term is very popular, with 14 recorded sales above $10,000 and 172 sales of $1000 or more. The top sale was MicroDesigns.com that sold for $67,000 in 2024 and Micromobility.com for $50,000 in 2018. Most sales are not using ‘micro’ in the unit sense, but rather as a term meaning small.
- The prefix nano is also well sold, with the top sale NanoSensor.com and several others related to nanotechnology, meaning technology at nanometer dimensions. There were 77 $1000+ domain sales recorded on NameBio with nano as a prefix.
- Even when the As A Prefix is used many sales not using the term as a true prefix get though, for example the sale of decadent.com does pass for ‘deca’ since ‘dent’ is a word. For this reason, the large number of sales for ‘deca’ are misleading. The American spelling of this prefix is deka, but I used only the deca spelling in my table.
I was not sure what I would find when I began this analysis. While a few terms like mega, micro, nano and giga do relatively well by the measures, I don’t think in most cases it it is strongly related to the fact that the terms are official unit prefixes.
The standard prefixes are largely derived from Latin or Greek terms, and the branding use is no doubt related, as brand names sometimes build on meanings in Latin, Italian or another language.
Updates:
Mar. 27, 2025 'millionth' corrected to 'thousandth' in one place.
Thanks to dotDB, OpenCorporates and NameBio.
Last edited:
