Statistics How To

Ratio Scale: Definitions, Examples of Ratio Variables

Statistics Definitions > Ratio Scale / Ratio Data

What is a Ratio Scale?

ratio scale

Weight is measured on the ratio scale.

A ratio scale has all the properties of an interval scale. Ratio data on the ratio scale has measurable intervals. For example, the difference between a height of six feet and five feet is the same as the interval between two feet and three feet. Where the ratio scale differs from the interval scale is that it also has a meaningful zero. The zero in a ratio scale means that something doesn’t exist. For example, the zero in the Kelvin temperature scale means that heat does not exist at zero. Other examples of the ratio scale:

  • Age. The clock starts ticking when you are born, but an age of “0” technically means you don’t exist.
  • Weight. At 0 pounds, you would weight nothing and therefore wouldn’t exist.
  • Height. If you were 0″, you would have no height.
  • Sales figures. Sales of zero means that you sold nothing and so sales didn’t exist.
  • Quantity purchased. If you bought 0 items, then there were no quantities purchased.
  • Time measured from the “Big Bang.”

The Ratio Scale and Negative Numbers.

As the “0” in the ratio scale means the complete absence of anything, there are no negative numbers on this scale.

The Ratio Scale and Ratios.

As the name suggests, we can create meaningful ratios between numbers on a ratio scale.
For example, a count of how many tests you took last semester could be zero if you didn’t take any tests. However, if you took two exams this semester and four the last semester, you could say that the frequency of your test taking this semester was half what it was last semester.

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Ratio Scale: Definitions, Examples of Ratio Variables was last modified: October 15th, 2017 by Stephanie Glen

5 thoughts on “Ratio Scale: Definitions, Examples of Ratio Variables

  1. Paul Jose P

    I have a point of doubt regarding ratio scale. I am a social science researcher. My doubt is the following:
    Is an Index expressed as a ratio between two variables like the expected repayment of loans taken from a bank and the actual repayment of loan of some 28 countries for a number of years (say 10 years ) is a continuous variable (is it ratio scale) ?
    The Index = Expected repayment of loan/ Actual Repayment

  2. Andale Post author

    You do have a “ratio”, but the ratio scale is something different. A Ratio scale is just an interval scale with a meaningful zero. So the question you should be asking is…does your data meet the requirements for an interval scale? IF it does, and if the zero is meaningful, then it’s a ratio scale.