In Portuguese, the word voltage does not exist. Neither academic nor technical.

In engineering, Portuguese speakers refers to volt as electric tension or potential difference.

The word voltage was popularized in the Portuguese language because some places use 220V and others use 110V and people always had to ask if the "voltage" for the equipment is 110 or 220. So, it's kind of a nickname/shortcut for non-technical people to refer to electric tension.

What about in English academic engineering? Does the word voltage exist or is it just a shortcut/nickname for electric tension or potential difference?

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    \$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$
    – Dave Tweed
    Commented Sep 8, 2019 at 11:51
  • \$\begingroup\$ The word voltage does exist in practice and I see it the same way as the word deletar also does, that is, as an adaptation of a foreign word. Contrary to some nitpicking engineers, I see no problem with it. The same way I see no problem calling any physician a doutor, even those who don't hold a doctorate degree, simply because the term is doctor in the english language. \$\endgroup\$
    – Marc.2377
    Commented Sep 8, 2019 at 18:49
  • \$\begingroup\$ In Czech we call it tension too, not voltage. But I never felt the need to analyse it. :-) \$\endgroup\$
    – Al Kepp
    Commented Sep 9, 2019 at 23:24
  • \$\begingroup\$ All I could think of while reading this page is the Blue Öyster Cult (American rock band) song "Godzilla". With a purposeful grimace and a terrible sound / He pulls the spitting high-tension wires down :) \$\endgroup\$
    – B Layer
    Commented Jan 26, 2020 at 6:47
  • \$\begingroup\$ @vianna77 I have to note that your assumption that "the word voltage does not exist" applies, maybe, only to Portugal's Portuguese. PT-br is more prone to accept this type of "creation" than PT-pt; "voltagem" is a accepted word in Brazilian Portuguese; this word figures in the official vocabulary from Brazilian Letters Academy. The same vocabulary also accepts "amperagem"; personally, I prefer "diferença de tensão" e "corrente"; the official pt-br doesn't accept "wattagem" (although sometimes we can hear someone saying "wattagem" in Brazil - it hurt my ears). \$\endgroup\$
    – mguima
    Commented Nov 3, 2020 at 22:08

5 Answers 5


In the International System of Units (SI) and the corresponding International System of Quantities, as described in the international standards series ISO/IEC* 80000 Quantities and units, quantities are always independent of the unit in which they are expressed; therefore, a quantity name shall not reflect the name of any corresponding unit.

However, ISO 80000 Part 1 General as well as IEC 80000 Part 6 Electromagnetism note that the name “voltage” is commonly used in the English language and that this use is an exception from the principle that a quantity name should not refer to any name of unit. It is recommended to use the name “electric tension” wherever possible.

IEC 80000 Part 6 Electromagnetism

The same information can be found in the series IEC 60050 International Electrotechnical Vocabulary (IEV), especially IEC 60050-121.

* The International Organization for Standardization (ISO) collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

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    \$\begingroup\$ I always believe the standard bodies must have considered the problem, but I'm not familiar with these standards. Good to see the answer from a physicist. Personally I think this should be the accepted answer, as it is the only answer that is able to cite relevant scientific/industrial standards from ISO and IEC. \$\endgroup\$ Commented Sep 8, 2019 at 9:50

Yes, voltage is a technical word in English.

From Wordnik:

noun A measure of the difference in electric potential between two points in space, a material, or an electric circuit, expressed in volts.

In fact, Wikipedia even lists "electric tension" as a synonym, though I hadn't heard that before. Mostly it's referred to as voltage or potential difference.

Some other answers have noted that Electric Tension was used to describe a potential difference until the mid-20th century in England, but it went out of popularity.

Google’s Ngram shows that voltage is far more popular than Electric Tension ever was, though.

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    \$\begingroup\$ "tension" is kind of an old-fashioned word for it; you see things on old schematics from the tube era marked H.T. for high tension (referring to a high voltage supply) for instance. I understand it still gets used among electricians sometimes, though it's rare in electrical engineering. \$\endgroup\$
    – Hearth
    Commented Sep 6, 2019 at 13:19
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    \$\begingroup\$ It most likely comes from the French. "Tension" in France is used in the same way "Voltage" is used in English speaking countries. We use "Voltage" sometimes too, but a lot less often. \$\endgroup\$
    – Harnex
    Commented Sep 6, 2019 at 13:39
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    \$\begingroup\$ Also, high voltage power lines may occasionally be referred to as "high tension" power lines in the US. \$\endgroup\$
    – user57037
    Commented Sep 6, 2019 at 17:59
  • \$\begingroup\$ @Harnex It may come from French, but it may also come from any number of other languages; I understand English is in the minority using the word voltage instead of some variant of the local word for "tension". \$\endgroup\$
    – Hearth
    Commented Sep 8, 2019 at 1:38

The water analogy of electricity was historically influential, both terms, "tension" and "current", were the result of this analogy.

In the early 1900s, "tension" was the standard technical term in English for electric potential. The B+ of a vacuum tube was called High Tension (HT), and a Cathode Ray Tube required "Extra-High Tension" (EHT) to operate. For some reasons, the word "tension" in English became obsolete in the middle of the 20th century (I cannot find a reference), and the term "voltage" became the standard technical term instead. Similarly, the old technical term for a "capacitor" was "condenser". A microphone that works by the change of capacitance was (and still is) called a "condenser microphone". In 1926, the term "condenser" was abandoned in English, but it took a generation or two to pick up the new term, fully replaced the old term around mid-20th century.

However, the translation of basic terms in electrical engineering to other languages was done long before this transition, so in many other languages, the technical term is still "tension" or "pressure", and a "capacitor" is still a "condenser".

The main reason seemed to be an effort to reduce the confusion between electrical engineering and mechanical engineering terms. Early 1900s was still the heyday of steam engines, and the confusion could be very real, and I fully understand the choice for "capacitor" over "condenser". But I think the choice "voltage", from a physical sense, is very unfortunate. Most physical quantities, as physical phenomena, have their own names independent from their units of measurement. When we talk about force as a phenomenon, we don't refer it as "newtonage", neither we use "wattage" for power.

$$\require{cancel}$$ \begin{array} {|l|l|l|l|} \hline \text{Phenomenon} &\text{Name} &\text{Unit} &\text{Numerical Name}\\ \hline \text{A push} &\text{force} &\text{newton} &\text{-}\\ \text{Flow of charge} &\text{current} &\text{ampere} &\text{amperage}\\ \text{Rate of work} &\text{power} &\text{watt} &\text{wattage} \\ \text{Electric Potential} &\cancel{tension} \text{voltage (!!)} &\text{volt} &\text{voltage (!!)} \\ \hline \end{array}

The introduction of "voltage" makes electric potential lost its own name, making it the only physical quantity named after its unit of measurement in English.

However, "voltage" is the standard term English, we have to follow it all along...

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    \$\begingroup\$ "Wattage" is a perfectly normal word. It's perhaps even more common amongst non-engineers who can read a value in watts but don't know that it is a measure of power. \$\endgroup\$
    – Graham
    Commented Sep 6, 2019 at 21:51
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    \$\begingroup\$ @Graham Yes, it's a normal word. But when we say "power", the physical definition "rate of doing work" is emphasized (e.g. "power dissipation", a "power resistor", is not called a "wattage resistor") and when we say "wattage", we refer to the numerical value of power (e.g. this appliance is too high for the wiring, basically a comparison of numbers). Same for "amperage", which is a perfectly fine word to talk about the numerical value of "current" displayed from a meter. But "voltage" is the only odd exception. \$\endgroup\$ Commented Sep 7, 2019 at 2:54
  • \$\begingroup\$ @比尔盖子 "high-wattage resistor" sounds acceptable to my ears, though you're correct that just "wattage resistor" does not. I think the difference is that wattage can only be used as a noun, while power can be either a noun or an adjective. \$\endgroup\$
    – Hearth
    Commented Sep 8, 2019 at 1:37

Yes. They do exist. In fact, voltage is actually potential difference. When you say voltage at a point is 5 V, we mean to say the potential difference of 5 V with respect to ground.

in another case, when there are two points at not zero potential, and we have to measure the voltage between those two points, we say "voltage is … V with respect to another point".

If one point (point A) is at 20 V and another point (point B) is at 25 V, we say voltage at point B is 5 V with respect to point A. And this is of course the potential difference between those two points.


In my physics experience, I've seen both the words voltage and potential difference used. I've never heard of the word electric tension in any context. Potential difference was more specific to situations where the relative voltage, or,

$$\Delta V = V_1 - V_2$$

was the important quantity desired, while voltage referred to a single reference measurement, or the above difference, based on context, which could often be inferred from the nature of the problem.

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    \$\begingroup\$ The phrase "high-tension wires" is commonly used in the U.S. in reference to the cables strung between very tall structures for long-range power distribution, and I think "high tension" it's used in British though not American automotive terminology to describe automotive spark plug wires ("HT leads"). \$\endgroup\$
    – supercat
    Commented Sep 7, 2019 at 18:19

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