How can you calculate human population growth?

Hint: The rise in the number of people in a country is population growth. The growth of the global human population is about \[83\]million a year, or $1.1$ percent per annum. The world's population grew from \[1{\text{ }}billion{\text{ }}in{\text{ }}1800{\text{ }}to{\text{ }}7.8{\text{ }}billion{\text{ }}in{\text{ }}2020.\]

Complete answer:
The "population growth rate is the rate at which in a given time frame the number of persons in a population grows, calculated as a fraction of the original population. Specifically, demographic growth rate refers to the population transition over a unit period, often calculated at the beginning of that period as a measure of the number of people in the population. This can be written as the formula, which is true for a short enough time interval:

A positive growth rate suggests a rise in the population, while a negative growth rate indicates a decline in the population. A zero growth ratio means that at the beginning and end of the period there is the same number of people. Even though there are substantial differences in birth rates, mortality rates, immigration rates, and age spread between the two times, a growth factor will be zero.

Population growth rate = \[P\left( {{t_2}} \right){\text{ }}-{\text{ }}P\left( {{t_1}} \right){\text{ }}/{\text{ }}P\left( {{t_1}} \right){\text{ }}\left( {{t_2}-{\text{ }}{t_1}} \right)\]

A positive growth rate suggests a rise in the population, while a negative growth rate indicates a decline in the population. A zero growth ratio means that at the beginning and end of the period there is the same number of people. A growth rate will be zero even though there are substantial increases in birth rates, death rates, immigration rates, and age spread between the two periods

Note: Net reproductive rate (r) is calculated as: r = (births-deaths)/population size. To get in percentage terms. Any scientist argues the capacity carries \[10.5{\text{ }}billion\](of this planet). Some countries, however, are pushing this cap by damaging the biosphere.