Per mil

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A per mil or per mille (also spelled permil, per mill or promille) (Latin, literally meaning 'for (every) thousand') is a tenth of a percent or one part per thousand. It is written with the sign ‰ (Unicode U+2030)., which looks like a percent sign (%) 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= ¹⁄₁₀₀₀ = 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.

[edit] Examples

A railroad distance sign in the Czech Republic with a 20‰ grade, which is equivalent to 2%

Examples of common use are:

• Blood alcohol content (in some countries)
• Seawater salinity. For example "the average salinity is 35‰".
• Tunnel and railway gradients (in some countries)
• Birth and death rates.
• Baseball batting averages, colloquially
• When used to describe property taxation in the U.S., it is called the millage rate. In Canada this is simply called the mill rate.

[edit] Related units

• Percentage point
• Percent (%) 1 part in 100
• Basis point (‱) 1 part in 10,000
• Parts per million (ppm)
• Parts per billion (ppb)
• Parts per trillion (ppt)

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