ratio scale

n. A quantitative scale including all three key scale properties: magnitude, equal intervals, 
and an absolute zero. All mathematical calculations are appropriate for ratio data. For example, money or income is measured on a ratio scale. The absolute zero represents no money and $50 is twice as much as $25; there are equal intervals as the difference of a dollar means the same thing when comparing $1 to $2 or $100 to $101. The large number of available calculations with a ratio scale makes it one of the most useful measures of quantitative data. – BJM

▶ See also ORDINAL SCALE