Types of Variables - Continuous

Continuous Variables

A continuous variable can take on any score or value within a measurement scale. In addition, the difference between each of the values has a real meaning. Familiar types of continuous variables are income, temperature, height, weight, and distance. There are two main types of continuous variables, interval and ratio.

The first type of continuous variable is the interval variable, a variable which can be ordered, and in which the distance or level between each category is equal and static. Using an income question as an example, income could be a variable about temperature using the Fahrenheit scale.

Interval Variable Example

What is the average daytime temperature during the summer in Tucson?

  • 99 degrees
  • 100 degrees
  • 101 degrees
  • 102 degrees
  • 103 degrees
  • 104 degrees
  • 105 degrees


Another type of continuous variable is a ratio variable, which is similar to an interval variable with one difference: the ratio of the scores makes sense. Let’s say respondents were being surveyed about their stress levels on a scale of 0-10. A respondent with a stress level of 10 should have twice the stress experienced as a respondent who selected a stress level of 5. A ratio variable needs to have a clear 0 point. Age, height, and weight are also good examples of ratio variables. Someone who is 6’0” tall is twice as tall as someone who is 3’0” tall. 

Ratio Variable Example


Please select your child's weight.

  • 65 lbs
  • 70 lbs
  • 80 lbs
  • 90 lbs
  • 95 lbs



      Test your knowledge of Types of Variables                         Explore Additional Resources