Ratio Scale: Definiton, Method and Examples

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In research, levels of measurement are used to determine how precisely the variables of the experiment are recorded. The approach you use to analyze your data depends on the level of measurement of the variable. 

There are 4 levels of measurement ranked in the order of complexity and precision – from low, nominal, to high, ratio. 

In market research, markets often use these 4 levels of measurement while collecting data via surveys. Amongst the 4 levels, marketers use the ratio scale as it possesses the qualities of the other scales as well. 

In this article, we will discuss the ratio scale in detail. 

What is a Ratio Scale?

A ratio scale ranks the highest in the four “levels of measurement” as described by S.S. Stevens. The ratio scale has all the qualities of nominal, ordinal, and interval scale. It is widely used in market research tools to get insights.

On a ratio scale, the data obtained can not only be categorized and ranked but also have equal intervals. A ratio scale has a true zero, that is, the zero possesses a meaningful value. The true zero value in a ratio scale makes it possible to describe the amount of magnitude.

 For instance, with a ratio scale, you can tell by how much distance the runner-up lost from the winner in a racing track.

A ratio scale gets its name from the fact that value is the estimation of the ratio between a magnitude of continuous quantity and a unit magnitude of the same kind. 

The common example of a ratio scale is length, duration, mass, money age, etc. For the purpose of marketing research, a ratio scale can be useful to evaluate sales, price, share, and a number of customers.

Characteristics of Ratio scale

Ratio Scale

For effective market research ratio scale is the most informative of all.  It can tell you about the order and the equal distance between two adjacent values. Also, the zero in the ratio scale has relevance, making it easy to tell the difference of “how much”.

A ratio scale allows all forms of statistical analysis. The variables in a ratio scale can be added, subtracted, multiplied, and divided. 

A ratio scale because of its true zero point does not have any negative number. Hence, any data which needs to evaluate on a ratio scale must have a point zero characteristic.

Possess qualities of other scales. You can use a ratio scale to label the variables, arrange them in order and also find the equal distance between variables. 

The ratio Scale allows for unit conversion. British thermal units such as Joules, kilogram-calories, or gram-calories, are ratio scale units. These units of energy can be converted to calculate the flow of energy. 

The ratio scale can be continuous or discrete. It can be represented in countable numbers (discrete variable) or can have infinite values (continuous variable).

What is a True Zero in Ratio Scale?

The ratio scale has the advantage of its absolute zero characteristics. A true zero indicates an absolute absence of the variable of interest. 

Say, for instance, years of military experience is a ratio variable. A respondent can have zero years of military experience. 

The presence of true zero in your research scale enables you to measure the ratio of values. You can say that 30 years old Alex is twice the age of her niece 15 years old. 

Kelvin is an example of the ratio scale. The Kelvin scale has 0K, i.e., true zero, this means nothing can be colder than 0K. 

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How to measure Ratio scale

The data of a ratio scale permits almost all statistical analysis. After obtaining the required data you can collect descriptive and inferential statistics.

For descriptive statistics

  • Frequency distribution: To get a clear overview of your collected data you can group the data in a table or plot it in a graph. 
  • Central Tendency:  You can use mode, median, or mean to calculate your central tendency. 

A mode is the most repeating value in your data.

A median is a value that is exactly in the middle of your data.

A mean uses all the values of the data to give you a single number for the central tendency.

If you have normally distributed quantitative data, it is better to use mean because it uses a single value of your data to measure the result. 

  • Variability: The range, standard deviation, and variance are useful to indicate variability. 

For range, you need to subtract the lowest value from the highest value of your data.

A standard deviation tells you how far each score in your data lies from the mean on average. It is the average amount of variability.

A variance is the average squared deviation from the mean of your data. To find the variance of your data, square the standard deviation

A range is the easiest among all three to calculate. The standard deviation and variance are best calculated using a computer program. Through these two pose difficulty, standard deviation and variance are more informative.

For inferential statistics

If your ratio scale is of the normal distribution, parametric tests are best for analysis. Parametric tests let you make a stronger conclusion based on your data.

Some common examples are

  • T-test used for comparison of means. It requires 2 variables. 
  • ANOVA is also used for comparison of means. The requirement for this test is 3 or more samples.
  • Pearson’s r used for finding correlation. The requirement is 2 variables.
  • Simple linear regression for the purpose of regression requires 2 variables.

Other methods used to analyze ratio data:

There are many methods that can be applied to evaluate ratio data. Some of these techniques are as follows. 


Strength, Weakness, Opportunities & Threats analysis can help you understand which factors or areas you need to focus on and what you should be taking advantage of. 

TURF Analysis: 

Using TURF analysis you can analyze the ratio data of customers who have been offered particular services or offers. You can use this to analyze the impact of combining products & services. 


Understand the relationship between multiple variables across your ratio data by using a table. Brands can use this to determine the correlation between product performance & customers’ buying intent and make a data-driven business decision.

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Examples of Ratio scale

  1. One of the most common examples of a ratio scale is the Kelvin scale. A Kelvin scale possesses the true zero point. This means that, while 40 degrees is not twice hot as 20 degrees on a Celsius or Fahrenheit scale. In a Kelvin scale, 40K is twice as hot as 20K because of the presence of true zero.
  2. A ratio scale is generally used to gather data on age in a social survey. It uses the scale as follows to gather data

    – Younger than 20
    – 20-25
    – 25-30
    – Older than 30

  3. Ratio scale is also used in collecting online surveys to figure out how much time one spends on video-games.

    – Less than 1 hour
    – 1 to 2.5 hour
    – 2.5 to 4 hour
    – More than 4 hour

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A ratio scale is a widely used scale in market research studies due to its special feature; the absolute zero. The non-arbitrary zero makes it possible to easily calculate the value behind the attributes collected in the data for research. It also gives a more precise value.

Interval Vs Ratio Scale

Ratio data possess all the characteristics of interval data. This creates confusion between the two scales. So let’s point out some differences between interval and ratio scales. 

In an Interval Scale, the difference between the data has meaning. However, the ratio between the variables has no meaning. 

In a Ratio Scale, the difference between variables and the ratio both have meaning. 

The zero in the Interval scale does not mean it’s absolute. This means while you can measure height as zero, you can also measure it in negatives. This does not give the interval scale the absolute zero characteristics. 

On a Ratio Scale, however, a zero indicates absolute zero. This means that if your data shows zero it doesn’t exist. 

To conclude; 

The ratio scale helps marketers conduct an inferential and descriptive analysis of their collected data. Using the right type of measurement scale can help you gather meaningful data and generate intelligent insights to make informed decisions. 

If you are looking for an online survey tool that can help you capture customer data, Voxco can help you design interactive, no-code surveys with engaging scales. You can also use our survey templates to start collecting data for any purpose. You can access our survey template library to check out what we offer. 

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