This question is about measurement units in languages written in right-to-left (RTL) scripts such as Arabic, Hebrew, Urdu, Malay, Farsi, etc. and their country-specific variants (for example, Arabic has quite a lot of national variants).

I would tend to think that there's a widely accepted practice in, say, Modern Standard Arabic, but I believe that not all countries have the same style regarding LTR text blocks when they include measurements (I've been told that some countries try to mimic English in this regard while others do not).

It is clear that numbers themselves flow from left to right, but there are two more things here: an optional -/+ sign and the measurement unit (e.g. celsius degrees, in this case: °C or ℃). In English we have:


As there are quite a few possibilities, I would need to have some feedback. So, the question is: What is the expected style in the different RTL language variants of the world?

These are the possibilities I can think of for the LTR text block containing the +/- sign, the figure and the measurement unit that would be preceded and/or followed by RTL text:



I would only need the units (with prefixes and suffixes) as I did above, without any Arabic text to avoid display issues. If possible, a reference (to some recognized style guide or something like that) would be great.

  • I'm voting to close this question as off-topic because this question is about typography, not linguistics. Note this proposal in Area 51: area51.stackexchange.com/proposals/88060/typography Commented Feb 25, 2016 at 8:58
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    My question is about spelling/punctuation, which is clearly the domain of language studies. It has nothing to do with typography, typesetting, printing or font design.
    – msoutopico
    Commented Feb 25, 2016 at 18:31
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    Spelling/punctuation are only marginally in the domain of linguistics as they are not about language so much as the technology used to represent language with visible marks. Commented Feb 25, 2016 at 20:37
  • Spelling and punctuation are part of linguistic graphology, which is the study of the systems of symbols (their units and how they interrelate) that are used to communicate language in written text. It is related to writing and reading, which are core disciplines of psycholinguistics. I don't see how it can be dismissed as a topic of interest for linguistic studies. Interestingly, it seems the Wikipedia includes orthography in the section of theoretical linguistics: en.wikipedia.org/wiki/Orthography
    – msoutopico
    Commented Feb 29, 2016 at 23:46
  • localisation != translation Order of symbols is not necessarily a property of a script or script direction. For example, within the Latin script, it is common to find both "10 USD" and "USD 10" and "$10" and "10$". Likewise in Arabic, it would not be surprising that more Francophone-influenced Arabic would follow fr-fr rather than en-uk conventions. Commented Mar 2, 2016 at 11:43

1 Answer 1


Even in RTL languages you are still writing numbers and numbers are LTR so when writing numbers we should treat them as LTR so -10°C is the correct way.

Consider the following example from Persian:

هوا نزدیک 10- بود

The temperature was nearly minus 10 degrees


most of the mathematical abbreviations are written exactly as they are written in Latin languages. for instance:


The speed of the car was 20 kilometers per hour

Or we can use both method like writing half of the abbreviation in Latin and the other half in Persian:

enter image description here


enter image description here

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    I have updated my answer Commented Feb 27, 2016 at 13:41
  • Thank you so much, Adel. That's exatly the kind of answer I was looking for. It would help me a lot if you could back up your explanation with some reference or authoritative source.
    – msoutopico
    Commented Feb 29, 2016 at 23:47
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    I have added a picture from translation of the book: Contemporary linguistics: An Introduction William O'Grady. Translation by: Ali Darzi I don't know if the example was enough but that was the only book I had access to. Commented Mar 2, 2016 at 5:29

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