readability - Is using a comma as a number separator a cultural thing?

In the US, it's very common to add a comma for numbers of more than 3 digits (ex: 1,000 for one thousand ; 1,000,000 for one million ; etc.).

In France though, we don't use this at all and commas are used for decimal numbers only (ex: 2,46).

Do you know which countries are following the US rule, and which countries are not? Where can I find resources on this?

Answer

Source - http://en.wikipedia.org/wiki/Decimal_mark

• In Albania, Belgium, Bosnia, Estonia, France, Finland, Hungary, Poland, Czech Republic, Slovakia and much of Latin Europe as well as French Canada: 1 234 567,89 (In Spain, in handwriting it is also common to use an upper comma: 1.234.567'89)


• In Brazil, Germany, Netherlands, Denmark, Italy, Portugal, Romania, Sweden, Slovenia, Greece and much of Europe: 1 234 567,89 or 1.234.567,89. In handwriting, 1˙234˙567,89 is also seen, but never in Denmark, the Netherlands, Portugal, Sweden or Slovenia. In Italy a straight apostrophe is also used in handwriting: 1'234'567,89.


• In Switzerland: There are two cases. 1'234'567.89 is used for currency values. An apostrophe as thousands separator along with a "." as decimal symbol. For other values the SI style 1 234 567,89 is used with a "," as decimal symbol. When handwriting, a straight apostrophe is often used as the thousands separator for non-currency values: 1'234'567,89.


• In English Canada, Ireland, Israel, Japan, Korea (both), Malaysia, New Zealand, Singapore, Taiwan, Thailand, the Philippines, the United Kingdom, and the United States: 1,234,567.89 or 1,234,567·89; the latter is generally found only in older, and especially handwritten, documents. Australia used this style up until the 1970s; now it uses the SI style.


• SI style: 1 234 567.89 or 1 234 567,89 (in their own publications the dot is used in the English version and the comma in the French version).



• In China, comma and space are used to mark digit groups because dot is used as decimal mark. There is no universal convention on digit grouping, so both thousands grouping and no digit grouping can be found. However, grouping can also be done every four digits: 123,4567.89, since names for large numbers in Chinese are based on powers of 10,000 (e.g. the next new word is for 108). Japan is similar.


• In Mexico: 1'234,567.89; for million separator an apostrophe is used.


• In India, due to a numeral system using lakhs (lacs) (1,00,000 equal to 100 000) and crores (1,00,00,000 equal to 10 000 000), comma is used at levels of thousand, lakh and crore, for example, 10 million (1 crore) would be written as 1,00,00,000.