Permille

A per mil or per mille (also spelled permil, per mill or promille) (Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. Through the Roman conquest, Latin spread throughout the Mediterranean and a large part of Europe...

, literally meaning 'for (every) thousand') is a tenth of a percent or one part per thousand. It is written with the sign ‰ (Unicode

Unicode

Unicode is a computing industry standard allowing computers to consistently represent and manipulate text expressed in most of the world's writing systems...

 U+2030)., which looks like a percent sign

Percent sign

The percent sign is the symbol used to indicate a percentage . It is represented in Unicode by ....

 (%) with an extra zero at the end. It can be seen as a stylized form of the three zeros in the denominator, although it originates from an alteration of the percent sign.

A per mil is defined as:

1‰ = 10⁻³= = 0.001 = 0.1%

A per mil should not be confused with ppm (commonly pronounced "parts per mil" in the United States).

A per mil or per mille (also spelled permil, per mill or promille) (Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. Through the Roman conquest, Latin spread throughout the Mediterranean and a large part of Europe...

, literally meaning 'for (every) thousand') is a tenth of a percent or one part per thousand. It is written with the sign ‰ (Unicode

Unicode

Unicode is a computing industry standard allowing computers to consistently represent and manipulate text expressed in most of the world's writing systems...

 U+2030)., which looks like a percent sign

Percent sign

The percent sign is the symbol used to indicate a percentage . It is represented in Unicode by ....

 (%) with an extra zero at the end. It can be seen as a stylized form of the three zeros in the denominator, although it originates from an alteration of the percent sign.

A per mil is defined as:

1‰ = 10⁻³= = 0.001 = 0.1%

A per mil should not be confused with ppm (commonly pronounced "parts per mil" in the United States). A measurement in ppm means parts per million, and has as its denominator 1,000,000 and not 1,000.

Examples

Examples of common use are:

• Blood alcohol content (in some countries)
• Seawater salinity
  Salinity
  Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
  
  . For example "the average salinity is 35‰".
• Tunnel
  Tunnel
  A tunnel is an underground passageway. The definition of what constitutes a tunnel is not universally agreed upon. However, in general tunnels are at least twice as long as they are wide. In addition, they should be completely enclosed on all sides, save for the openings at each end...
  
   and railway gradients (in some countries)
• Birth
  Birth rate
  Crude birth rate is the nativity or childbirths per 1,000 people per year.According to the United Nations' World Population Prospects: The 2008 Revision Population Database, crude birth rate is the Number of births over a given period divided by the person-years lived by the population over that...
  
   and death rates.
• Baseball batting average
  Batting average
  Batting average is a statistic in both cricket and baseball measuring the performance of cricket batsmen and baseball hitters, respectively. The two statistics are related, in that baseball averages are directly descended from the concept of cricket averages....
  
  s, colloquially
• When used to describe property tax
  Property tax
  Property tax, or millage tax, is an ad valorem tax that an owner is required to pay on the value of the property being taxed. Property tax can be defined as "generally, tax imposed by municipalities upon owners of property within their jurisdiction based on the value of such property."There are...
  
  ation in the U.S.
  United States
  The United States of America is a federal constitutional republic comprising fifty states and a federal district...
  
  , it is called the millage rate. In Canada
  Canada
  Canada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
  
   this is simply called the mill rate.

Related units

• Percentage point
  Percentage point
  Percentage points are the unit for the arithmetic difference of two percentages.Consider the following hypothetical example: in 1980, 40 percent of the population smoked, and in 1990 only 30 percent smoked...
  
  
• Percent (%) 1 part in 100
• Basis point
  Basis point
  A basis point is a unit relating to interest rates that is equal to 1/100th of a percentage point per annum. It is frequently but not exclusively used to express differences in interest rates of less than 1% pa. It avoids the ambiguity between relative and absolute discussions about rates...
  
    1 part in 10,000
• Parts-per notation
  Parts-per notation
  Parts-per notation is used, especially in science and engineering, to denote relative proportions in measured quantities; particularly in low-value proportions at the parts-per-million , parts-per-billion , and parts-per-trillion level...