Population Change Formula

Population change refers to a change in the number of people during a specific time period. The world population has not been stable. It has increased manifold. Population changes constantly due to birth rate and death rate and relocation of people in search of better sources of income. Population change is a continuous global phenomenon. Population Change Formula helps in analyzing this change in population. 30 years down the line, by 2050, the global population is expected to rise by 2 billion, from 7.7 billion to 9.7 billion. As per the recent UN report, by 2050, India is expected to add 273 million people.

Let us study the population change formula using solved examples in the following sections.

What is the Population Change Formula?

There are 4 major factors affecting Population change.
1. Birth rate
2. Death Rate
3. Immigration
4. Emigration

The population change is calculated by the formula given below:

Population change = (Births + Immigration) - (Deaths + Emigration)

Solved Examples Using Population Change Formula

Example 1: 

A country in Europe collected yearly data as given below. Can you calculate the 'population change' for the country?

Births - 20,000

Immigration - 5,000

Emigration - 7,000

Deaths - 21,000


We know, that the formula for the population change is:

Population change = (Births + Immigration) - (Deaths + Emigration)

= (20,000 + 5,000) - (21,000 + 7,000)

= 25,000 - 28000

= -3,000

There is negative growth in the population.

Answer: The population decreased by 3000 individuals.


Example 2: 

What factors increase the population size? List any four of them.


Factors that increase the size of a population are:

High birth rate

Low death rate

High immigration

Low emigration                                                                                                                                                                            

Answer: Population size is affected by several factors at play.