The decimal separator is a symbol used to mark the boundary between the integer and the fractional parts of a decimal numeral.

Originally (near the end of the 1st millennium CE), a bar over the units digit was used. Later, a separator (a short, roughly vertical, ink-stroke) between the units and tenths position became the norm. When type-set, it was convenient to use the existing comma, stop, or point marks for this purpose.

In many countries, therefore, the comma is used to mark the decimal units position; however, in predominantly English-speaking countries, a stop (.) or point (middle dot: ·) is commonly used as the decimal separator.

(For numeral systems other than decimal, the analogous point is known as a radix point.)

Examples of use:

• In France, the Netherlands, and much of Latin Europe: 1 234 567,89
• In Germany, Romania and much of Europe: 1 234 567,89 or 1.234.567,89 (in handwriting you may also come across 1^·234^·567,89)
• In Switzerland (mainly German-speaking Switzerland): 1'234'567,89
• In the United Kingdom and United States: 1,234,567.89 or 1,234,567·89; the latter is more commonly found in older, and especially handwritten, documents nowadays; many UK schools now teach the SI style.
• SI style: 1 234 567.89 (dot countries) or 1 234 567,89 (comma countries)

Dot countries

Countries where a dot is used to mark the radix point include:

Australia, Botswana, Canada (English-speaking), China, Costa Rica, Dominican Republic, El Salvador, Guatemala, Honduras, Hong Kong of the People's Republic of China, India, Ireland, Israel, Japan, Korea (both North and South), Malaysia, Mexico, Nicaragua, New Zealand, Panama, Philippines, Saudi Arabia, Singapore, Taiwan, Thailand, United Kingdom, United States (including insular area of Puerto Rico),

Comma countries

Countries where a comma is used to mark the radix point include:

Albania, Andorra, Argentina, Austria, Belarus, Belgium, Bolivia, Brazil, Bulgaria, Canada (French-speaking), Croatia, Cuba, Chile, Colombia, Czech Republic, Denmark, Ecuador, Estonia, Faroes, Finland, France, Germany, Greece, Greenland, Hungary, Indonesia, Iceland, Italy, Latvia, Lithuania, Luxembourg, Macedonia, Moldova, Netherlands, Norway, Paraguay, Peru, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, South Africa, Sweden, Switzerland, Ukraine, Uruguay, Venezuela, Zimbabwe

See also

• Algorism