Ratio data is a level of measurement that has equal intervals and a true zero point, allowing for meaningful operations such as multiplication and division (Katz, 2006a, 2006b).
The great benefit of ratio data is that it provides a true zero point. This allows for a full range of mathematical operations including multiplication and division, offering more detailed and meaningful analyses compared to other data levels. As Janicak and Zreiqat (2023) argue:
“Ratio data is the only scale in which the magniture between values on the scale exists. If one item weighs 10 pounds and the other 5 pounds, then it is correct to say that the first item is twice as heavy as the second.”
Examples include height in centimeters, weight in kilograms, and age in years, all of which have a true zero point and allow for meaningful mathematical operations.
A Scholarly Definition: “[Ratio data] follows numeric scales and has equal and definitive ratio between each data. It is measured as multiples of one another and, unlike interval data, can be multiplied or divided. No negative numerical values is considered in ratio data, and zero is considered as a point of origin.” (Nandi, Gypsy & Sharma, 2020)Ratio Data Examples
1. Weight
If an object weighs 0 grams (or 0 kilograms, or 0 pounds), it truly has no weight. You can also say that an object weighing 10 grams is twice as heavy as an object weighing 5 grams. This demonstrates both a true zero and meaningful ratios between measurements.
2. Height
The measurement of height in units like centimeters or feet also has a true zero. If something is 0 centimeters tall, it has no height. A tree that’s 20 meters tall is twice as tall as a tree that’s 10 meters tall.
3. Age
Age is measured from a defined point of starting, which is birth (age 0). If someone is 20 years old, they are twice as old as someone who is 10 years old.
4. Distance
If you measure the distance of a journey in miles or kilometers, a distance of 0 means no movement has occurred. A journey that is 100 kilometers long is twice as long as a journey that is 50 kilometers long.
5. Volume
Consider a container’s volume measured in liters or gallons. If a container holds 0 liters, it’s empty. A container holding 8 liters contains twice the volume of a container holding 4 liters.
6. Income
If someone earns $0, it means they have no income. An individual earning $200,000 annually earns twice as much as someone earning $100,000 annually.
7. Speed
If a vehicle is moving at 0 kilometers per hour (or 0 miles per hour), it’s at a standstill. A car traveling at 60 km/h is moving twice as fast as one traveling at 30 km/h.
8. Energy Consumption
Measured in units like kilowatt-hours (kWh) or joules. If an appliance consumes 0 kWh, it hasn’t used any energy. An appliance using 20 kWh has consumed twice the energy of one that has used 10 kWh.
9. Population
If a certain species has a population of 0 in a particular area, it means there are no individuals of that species present. A region with a population of 10,000 people has twice as many inhabitants as a region with 5,000 people.
10. Sound Intensity
This is often measured in decibels. A sound level of 0 decibels represents the threshold of hearing and is effectively no sound for the human ear. A sound that is 20 decibels is 10 times more intense than a sound that is 10 decibels due to the logarithmic scale of decibels, but the ratio is meaningful.
11. Temperature in Kelvin
Unlike Celsius or Fahrenheit, the Kelvin scale starts at a true zero point, absolute zero (0K), which is the theoretical absence of all thermal energy. A substance with a temperature of 200K has twice the thermal energy of a substance at 100K.
12. Production Quantities
In a manufacturing context, if 0 units are produced, it indicates no goods were manufactured. If one day 400 units are produced and another day 200 units are produced, the first day’s production is twice that of the second.
13. Battery Life
For electronic devices like smartphones or laptops, battery life can be measured in hours or percentage. A battery life of 0 hours or 0% indicates the device is fully drained. A device with a battery life of 8 hours has twice the remaining usage time as a device with 4 hours of battery life.
14. Disk Space
On a computer or digital storage device, the total storage or free space can be measured in bytes, kilobytes, megabytes, gigabytes, etc. A storage space of 0 GB means there’s no storage capacity. A hard drive with 500 GB of storage has twice the capacity as one with 250 GB.
15. Physical Force
Measured in units like newtons. If a force of 0 newtons is applied to an object, it means there’s no force being exerted. An applied force of 20 newtons is twice as much as a force of 10 newtons.
16. Light Intensity
This can be measured in lumens or candela. A light source emitting 0 lumens or candela effectively emits no light. A lamp emitting 200 lumens is twice as bright as a lamp emitting 100 lumens.
17. Concentration
In chemistry, concentration can be measured in molarity (moles per liter) or in parts per million (ppm). A solution with a concentration of 0 M or 0 ppm has none of the solute. A solution with 2 M concentration has twice the amount of solute as a solution with 1 M concentration.
18. Sales or Revenue
For businesses, the total sales or revenue can be measured in currency units like dollars, euros, etc. If a business reports $0 in sales, it means no sales were made. A business that earns $2 million in a month generates twice the revenue as one that earns $1 million in the same period.
Other Types of Data
There are four types of data, summarized in the table below:
| Data Type | Description | Example | Mathematical Operations |
|---|---|---|---|
| Nominal Data | Data categories that do not have a specific order or ranking (Wilson & Joye, 2016). They are simply used to label variables without any quantitative value. | Colors (red, blue, green), gender (male, female, non-binary), types of fruits (apple, banana, cherry). | Generally, no mathematical operations can be performed except counting (De Vaus, 2001). |
| Ordinal Data | Data categories with a meaningful order, but the distances between the categories are not defined or consistent (De Vaus, 2001). | Educational levels (high school, bachelor’s, master’s, doctorate), Likert scale responses (strongly disagree, disagree, neutral, agree, strongly agree). | Can be ranked or ordered, but addition or subtraction don’t make sense. |
| Interval Data | Data with a consistent order and a consistent interval between values. However, they don’t possess a true zero point (Babbie, Halley & Zaino, 2007). | Temperature in Celsius or Fahrenheit, IQ scores. | Addition and subtraction are meaningful, multiplication and division are not. |
| Ratio Data | Data that possess all the properties of interval data and, additionally, have a true zero point (Das, 2023; Stockemer, 2018). | Age, height, weight. | All mathematical operations are valid. |
References
Babbie, E., Halley, F., & Zaino, J. (2007). Adventures in Social Research: Data Analysis Using SPSS 14.0 and 15.0 for Windows (6th ed.). New York: SAGE Publications.
Das, A. P. (2023). Understanding Python Programming. Arpita Priyadarshini Das.
De Vaus, D. A. (2001). Research Design in Social Research. New York: SAGE Publications.
Janicak, C. A., & Zreiqat, M. (2023). Applied Statistics in Occupational Safety and Health. Bernan Press.
Katz, M. (2006). Study Design and Statistical Analysis: A Practical Guide for Clinicians. Cambridge: Cambridge University Press.
Katz, M. H. (2006). Multivariable analysis: A practical guide for clinicians. Cambridge: Cambridge University Press.
Nandi, R., Gypsy, K., & Sharma, K. (2020). Data Science Fundamentals and Practical Approaches. BPB Publications.
Stockemer, D. (2018). Quantitative Methods for the Social Sciences: A Practical Introduction with Examples in SPSS and Stata. London: Springer International Publishing.
Wilson, J. H., & Joye, S. W. (2016). Research Methods and Statistics: An Integrated Approach. New York: SAGE Publications.
Dr. Chris Drew is the founder of the Helpful Professor. He holds a PhD in education and has published over 20 articles in scholarly journals. He is the former editor of the Journal of Learning Development in Higher Education. [Image Descriptor: Photo of Chris]