Population terms and concepts


A group of individuals of the same species that occupies a particular geographic area.


The member of a particular nation, community, or ethnic group

Crude Birth Rate or Natality Rate

The number of live births per thousand people in a year.

Net Migration Rate

N = 1000 × (I – E) / P

N- Net Migration Rate

E- Number of People emigrating out of the country

I- Number of people immigrating into the country

P-estimated mid-year population

Fertility Rate

The number of live births expected per 1000 women in their lifetime in a specific geographic area and specific point of time, that is usually a calendar year.

Niger has the highest fertility rate of 6.49. Singapore has the lowest fertility rate of 0.83.

Dependency Ratio

Number of dependents in a population divided by the number of working-age people.

It’s a calculation which groups those aged under 15 with those over 65 years as the dependents and classifies those aged 15-64 years as the working-age population.

Growth Rate

Growth Rate = CBR – CDR +/- Net Migration Rate/ 1000.

South Sudan has the highest population growth rate of 3.83% in 2017.

Rate of Natural Increase (RNI)

Rate of Natural Increase (RNI) = CBR-CDR (No Migration)

CBR>CDR = ↑ population

RNI usually expressed as % e.g., 2% = 2/100 = 20/1000

RNI ≠ population growth if migration significant

Crude Death Rate (Mortality Rate)

Number of Deaths per thousand people in a year.

Adult Literacy Rate(ALI)

It is a statistical measure used to determine how many adults can read and write in a specific area or nation. Adult literacy is one of the factors in measuring the Human Development Index (HDI) of each nation,

Along with life expectancy, education, and standard of living. Burkina Faso has the lowest literacy rate of 21.8% (2015).

Life Expectancy Rate

Life expectancy equals the average number of years a person born in a given country is expected to live.

Monaco has the highest life expectancy rate at 89.52 in the year 2015. Chad has the lowest life expectancy rate at 49.81.

Population Concepts


A situation whereby the population is considered too large for the available resources.

Under – population

A situation where the population is less than the available resources of a country.

Optimum Population

A situation where the number of people that can be supported is the same as the available resources.

* * All the Notes in this blog, are referred from Tamil Nadu State Board Books and Samacheer Kalvi Books. Kindly check with the original Tamil Nadu state board books and Ncert Books.