On average, population density indicates the number of people who populate a given area or city. This information can be useful for identifying the resources necessary for the correct development of a populated area or for comparing different areas. To calculate this information, you need to acquire data relating to the geographical extension of the area in question and the number of people who populate it. The formula for obtaining the population density is as follows: Population density = Number of people / Surface of the populated area.
Steps
Part 1 of 3: Collect the Data
Step 1. Define the area to study
Find the boundaries of the area or region whose population density you want to calculate. To do this, refer to why you want to calculate this figure. For example, you may need to calculate the population density of your state, city or neighborhood. One of the main information is the surface covered by these places, usually expressed in meters or square kilometers.
- Most likely this has been calculated in the past, so search using an encyclopedia or the web.
- Identify if the area in question already has well-defined boundaries. If not, you will have to define them yourself. For example, if you want to calculate the population density of your neighborhood, its surface may not yet have been surveyed by anyone, so you will have to calculate it yourself starting with drawing its boundaries.
Step 2. Determine the population of your study area
Instead of carrying out a population census, look for an up-to-date register that contains the total number of individuals who populate the area in question. Find this information through a web search. Let's assume we want to calculate the population density of the city of Milan in Italy. Look for the most up-to-date data on the population of this metropolis. If you are looking for this data for a country, the CIA website is a great resource.
If you are calculating the population density of an area that has not yet been surveyed, you will need to do the population count yourself. This is the case if for example you want to study a neighborhood in your city or calculate the population density of kangaroos in a certain area of the Australian outback. Whatever your goal, try to get as accurate a number as possible
Step 3. Check the compatibility of the data obtained
If your purpose is to make comparisons between different areas, make sure that the data acquired is expressed using the same units of measurement. For example, if the area of one province is expressed in square miles, while a second is expressed in square kilometers, you will first need to convert both of these data into square miles or square kilometers.
To easily perform these types of conversions, visit the following website
Part 2 of 3: Calculating the Population Density
Step 1. Learn the math formula
To calculate population density, divide the number of individuals by the size of the area occupied. The formula is therefore the following: Population density = Number of people / Surface of the inhabited area.
- The unit of measurement for area could be square kilometers or square miles. If you are calculating the population density of a limited area, you can also use square meters or square feet. If you are doing a study for academic or professional purposes, it is best to use the standard units of measurement: kilometers or square miles.
- The unit of measure for expressing population density is inhabitants per unit area. For example, 2000 individuals per square kilometer.
Step 2. Enter your details into the formula
At this point you should know both the number of individuals that make up the population under study, and the surface of the area they inhabit. For example, if 145,000 people live in city A and the urban area covers 9 square kilometers, we will have 145,000 / 9 square kilometers.
Step 3. Perform the calculations
You can perform the division manually or rely on a calculator. In our example, we must divide 145,000 by 9 to obtain a population density of 16,111 inhabitants per square kilometer.
Part 3 of 3: Interpreting the Results
Step 1. Compare population density
Compare the population densities of different areas to get more information about them. For example, if city B has 60,000 people spread over an area of 8 square kilometers, its population density is 7,500 people per square kilometer. Comparing this data with the previous example we can deduce that city A has a population density significantly higher than that of city B. Evaluate whether it is possible to use this information to draw more conclusions regarding the two cities in question.
Even calculating the population density of a heavily inhabited area, such as a large city, the result obtained does not provide any information on the differences between the individual neighborhoods. To have a better understanding of a city, you need to be able to compare the population density of the individual areas that make it up
Step 2. Try to include the population growth rate as well
Calculate the expected growth rate of the population present in the area under study, then proceed to compare the current population density with those estimated in future years. Search past data to attempt a comparison between current and past population densities. This will help you better understand how a particular area has changed over time and try to predict how it will change in the future.
Step 3. Be aware of the limitations of this information
This method of calculating population density is very simple and straightforward, but it does not reveal detailed information about a particular area. This factor is highly dependent on the size and type of place whose population density is being calculated. Sometimes the formula used better describes small and sparsely populated areas than very large areas that include both areas with a high population density and areas that are almost uninhabited.
- Suppose we calculate the population density of a province that includes open spaces, forests and even a large metropolis. In this case the population density of this area will not give us detailed information regarding the population that inhabits the city, that is, the space actually inhabited and used by people.
- Remember that population density is simply an average of the individuals that populate a given area. In fact, it may not exactly correspond to the population present in a given place; in this case try to evaluate the reasons. Try to divide the area into smaller spaces and then proceed to calculate the individual population densities.
Step 4. Analyze the data obtained
When you know the data regarding the population density of an area, you can make future predictions. For example, areas with a high population density tend to have higher crime rates, housing prices and commodity costs than areas with a lower density. The latter, on the other hand, tend to exploit agricultural resources more and are often characterized by large uninhabited open spaces. The conclusions you can draw about the area or areas that are the subject of your study depend on your original purpose. Always try to use the obtained data in the most intelligent and useful way possible.
Advice
- Compare the data you found with other population density reports. If the value you obtained differs from the data listed, look for possible calculation errors or anomalous variations in population density over time.
- It uses the same formula to find out the population density of animals, such as livestock.
