Math Percentage calculation Percentage and Per mille

Percentage

Percent (%) means hundredth or "of hundred". The following applies:

$p\%=\frac{p}{100}$

Examples

  • $1\%=\frac1{100}=0.01$
  • $100\%=\frac{100}{100}=1$
  • $25\%=\frac{25}{100}=0.25$
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Hint

Percentage information is used to
  • indicate proportions of a whole.
    (e. g.: "40% of the respondents are female")
  • or
  • indicate increases and decreases.
    (e. g.: "the revenue increased by 20 percent")

Per mille

Per mille (‰) means thousandth or “of thousand”. The following applies:

$p‰=\frac{p}{1000}$

Examples

  • $1‰=\frac1{1000}=0.001$
  • $250‰=\frac{250}{1000}=0.25$
  • $1000‰=\frac{1000}{1000}=1$
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Hint

In order to convert per mille to percentage, divide by 10.

Example: $10‰=\frac{10\color{red}{:10}}{1000\color{red}{:10}}=\frac{1}{100}=1\%$