Writing Numbers – Periods or Commas?

08 Feb 2015
(comments: 16)
Use of periods and commas in numbers

One of the most common mistakes I see when proofreading bilingual annual reports (German/English) is that the periods and commas are placed incorrectly as delimiters in numbers and figures.

When writing figures, German speakers sometimes forget that the symbols used are different in German and English. In both German and in US/UK English, commas and points are used; they are, however, placed differently in the two languages.
Please note that there are different conventions when it comes to writing numbers, both in German (e.g. Duden or DIN standard DIN 5008), and in the different versions of English (UK, Canada, South Africa, etc.). For the sake of clarity I have boiled this complex topic down to the following rules for German and US/UK English when it comes to writing figures, e.g. in multilingual financial reports:

1. Symbol for the “decimal separator”

  • In German: „EUR 999,50“ or „EUR 2,5 Millionen“
  • In English: “EUR 999.50” or “EUR 2.5 million”

Notice how in UK/US English a decimal point, and not a comma, is placed as separator before the cents (the fractional part of the decimal number).

2. Symbol for the “thousands separator”

  • In German: „US-$ 400.456,50“
  • In English: “US-$ 400,456.50”

Notice how in US/UK English a comma, and not a point, is placed as a 3-digit group separator.

By the way:

To avoid confusion, especially in international documents, in recent years the use of spaces for digit grouping (preferably a "thin space") has been advocated in numerous German and English style sheets and standards. Example:

  • In English: “The yearly water consumption in New York is 42 705 gallons on average per capita.”
  • In German: „Der jährliche Wasserverbrauch in New York beträgt durchschnittlich 161 655 Liter pro Kopf.“

Which brings me to the next challenge: Different international measuring units – but that's another story for another day!

This might also interest you

What is an Oxford comma (serial comma)?

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Comment by Michael |

my son is studying maths in Germany after just moving from the UK. We were familiar with the use of a comma instead of a decimal point but hadn't realised that a dot, instead of an x, is used to signify multiplication and that a colon is used instead of the usual division symbol. Lots of scope for silly mistakes!
That said, when I was at school in the seventies, we also used a dot to signify multiplication.
Like Vic above, I grew up in a world where 1million = 10^6, 1billion = 10^12 and 1trillion = 10^18 and I still understand these values to this day. I also see the serial comma as ugly and would just re-write the sentence in an unambiguous way..

Comment by Vic |

All this goes to show how enjoyable and wonderful language is whilst being simultaneously annoying and frustrating. ;-)

I found William's comment regarding the 'ions very interesting. As a young English boy back in the late 40's, the system I also learnt was that large named numbers increased not just in 'ions but in Millions. So eg a Billion was a million million i.e. Million^2 and a Trillion was a Million Billion = Million^3 and so on and that this new fangled Billion (1 000 000 000) was just an Americanism. After all they seemed to want to change everything else that the English historically held dear, but these articles and comments demonstrate a new view for me and thanks for that.

In the article the piece about the Oxford Comma seemed to me a little confusing, in that you find it confusing.

(Oxford comma:

" I immediately called my superiors, Sally and Michael. "

This sentence could either mean that the speaker called his superiors, as well as Sally and Michael, or that Sally and Michael are in fact the speaker’s superiors. By using an Oxford comma in this sentence, one could clarify that one means the former: I immediately called my superiors, Sally, and Michael.)

To me the sentence seems fine and that the speaker clearly intended the former, simply because a comma was used to separate the two. Had the speaker intended the latter the comma would not have been used.

Sometimes language can be uncertain, conflicting or even contradictory but the correct use of punctuation usually get one through. In this case I would have thought that the use of punctuation immediately prior of a conjunction would itself cause confusion because the use of a comma at this point would be to attempt to correct a potential misunderstanding regarding a previous punctuation mark and I agree that using a serial comma like this is a capital sin.

Comment by Jalad |

Hi, When we write some value in kilogram. For example "4.5 kilogram". I think the value should be written with "." as Kilogram is English. Please correct me If I am wrong, do we write it as "4,5 kilogram" in german.

Reply by Liz Naithani

Yes, in German one would write “4,5 kg“.

Comment by William |

I actually didn't know that placement of commas or periods/dots between digits should be the same in UK English as it is in US English. I've always thought that UK English follows the same pattern as most European 'numeral languages' do, while English speaking countries outside of Europe, except for some Asian countries like India, basically reverse the system by 'swapping' the commas and periods for their functions. Where I come from (the Netherlands), we use either periods as group separators for thousands, millions, etc. and sometimes no periods at all (allthough not preferred), and commas to separate regular number digits from digits worth smaller than units (tenths, hundredths, thousandths, etc.). I don't have a big problem with that, because I think that most people from other regions of the world who speak Enlish will understand which number you're trying to share with them if both periods and a comma are present in the same number.

A bigger problem is translating very large or very small numbers with factors of 10 to the power of 6 or -6 and beyond. A lot of European Non-English native speaking countries, especially in germanic languages such as Dutch, German and Danish, and some romanic languages like French, use a system for grouping their numerals in terms of pronouncing them different from what (at the most, I guess) English native speakers do. In English, the number of digits involved in the 'advance' of calling out numbers larger than the thousands in each group is 3. For example 1,000,000 is one million, 1,000,000,000 is one billion.
In the other languages mentioned earlier, however, the group is not as big as digits, but 6 digits, with an extra kind of interval after each group of 3 digits. I've read somewhere that this has also been the system in variants of English in the past, but that it has been banned. If I'm not mistaken, the UK may be one of the last countries on Earth to ban this method, but I'm not sure about this. As a few examples to this system, 1,000,000 is still one million, but 1,000,000,000 is one milliard (literally translated) instead of one billion, while one billion in those non-English speaking countries in Europe is equal to 1,000,000,000,000, which is one trillion in English. This often brings confusion when translating numerals from non-English to English and vice versa. Very often I have to correct myself when I tend to translate the number 1,000,000,000,000 to English as 'one billion'.

To summarize; In English the order, with advance of 3 digits each beyond the thousands is: millions, billions, trillions, quadrillions, etc.
In languages like Dutch or German, however, the order, with advance of 3 digits each beyond the thousands is (literally translated): millions, milliards, billions, billiards, trillions, trilliards, quadrillions, quadrilliards, etc. This means that each first group of 3 digits beyond the thousands is called something that ends with '-ions', and that the group of 3 digits following the '-ions' is called something that ends with '-iards'. So, the groups actually represent an advance of 6 digits each with an interval after half that group (3 digits) causing to change the last part of the word.
This may not make perfect sense to English native speakers, but feel free to react if you need better clarifications.

Comment by Ayesha |

its amazing information – thank you!

Comment by Ana |

Can you explain/interpret:

Metric number (mn) 15,9/2/4
I will assume 15,9 is 15.9mn.
What does /2/4 mean?

Reply by Liz Naithani

Hi Ana,

Yes, 15,9 in a German text would be equivalent to 15.9 in an English text.

About the figure with the slashes: To be honest – I have no idea! :-)
What is the context that this figure is being used? I am only aware of slashes being used in the context of date formatting: dd/mm/yyyy (e.g. 17/05/2019 --> 17 May 2019) – unless it's used to indicate a fraction (e.g. ½, ⅓). Also see https://en.wikipedia.org/wiki/Slash_(punctuation)#Mathematics

Comment by Ashu |

On the University website, fees was written as 129.40 euro.
What does that mean hundred and twenty nine Euro and 40 cents OR approx thirteen thousand? Because there's a point after two places from right so that can't be depicted as comma. Please help me.. confused a lot.

Reply by Liz Naithani

Yes, "129.40 Euro" means 129 Euro and 40 Cents.

Comment by Tom |

With reference to "COMMENT BY ANONYMOUS | 2017-09-02"
In South Africa the SI and ISO standards are enforced. This is a boon.
No gm or gms for grams, or KM for kilometers, or L for litres or any such oddities are tolerated.
Mark your product with 'gm' for grams and expect a serious 'notification' from Standards.
The South African keyboard has the '1/2 space' for the thousands separator. This is used by all.

Comment by useful informaton. |

We are planning to sign a contract in English language with a Germany company. But the figures are written like EUR 310.500,00. The lawyer asked us to change that writing style as: 31,500.00.

Comment by Aztekium.pl |

Very interesting article! Usefull informations!

Comment by Peter |

In fact Anonymous is partly right. British Standard 303 (now superceded by BS 8888) introduced the European standard of writing numbers in the early 1970s (about the same time that the UK abandoned the long billion). BS 308 was originally primarily for technical drawings, but I believe that BS 8888 extends to other documentation relating to design.
There has been some spread of the European type format for numbers outside of the realm of physical engineering.
So, in engineering in the UK, the decimal point, "." has been supplanted by the comma; the thousands separating comma "," has been supplanted by spaces, and so on. Unfortunately, none of this seems to be taught in schools, so a quick re-education of new newcomers to engineering is the norm.
I hope that the old UK system of writing numbers gives way to the more sensible, more common standard in the same way that feet and pounds are disappearing in favour of metres and kilograms.

Comment by Eden |

Thank you for the article. As a American scientist and bilingual technical communicator, I am often troubled on how to make sure my figures are correctly interpreted. Any idea as to how/why this this division occurred?

In response, to Travis:
84.3 is correctly said: eighty-four point three. In German, 84 komma 3 (vierundachtzig komma drei)
84 and 3 is incorrect because it's not precise. In this usage, it implies mathematical operation, ie 84 + 3=87. Historically, the numerical "and" was used with tens digits, ie 4 and 20 = 24. In German, the numbering is also this way, vierundzwanzig.
843 in English: eight hundred forty-three.

Comment by Travis |

Question, in the US, a number like 84.3 would be written "eighty-four and three." I'm having Europeans insist there "eighty-four and three" would be 843. Also there has been heavy dispute on common practice vs. grammatical law. Would this law of 'and' meaning a decimal by the proper grammar of English extend to British English, or just American English grammar? Again, not looking for what most people use as mist people don't follow all the rules to proper linguistics, asking what's actually correct.

Note, security question is a quack, asking to add 5 and 6 isn't always 11, my answer of 56 is actually correct. 11 would be the sum.

Comment by abdul rahimov |

incidentally in russia, the separator for thousands -- 3 digit increments -- is the period, while the separator for decimals is the comma. the opposite of US practice.

Comment by Anonymous wrong wrong wrong! |

Obviously Anonymous is incorrect and anyone who has been to any of these countries would know!

Comment by Anonymous |

This information is incorrect. The decimal separator is not a dot in English, but in the United States and the United Kingdom, in South Africa (where the official language is English) for example they use the comma as the decimal separator, just like most of the rest of the civilised world.

Reply by Liz Naithani

Well, let's say the information is not complete. :-)
Thanks for the pointer – I must admit that so far I haven't worked on any project with South African English. Anyway, I updated the article to make it more precise.

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