Population Change Basics

Birth Rate (BR) = the number of live births per 1000 people per year

Death Rate (DR) = the number of deaths per 1000 people per year

Fertility Rate = the average number of children a woman will have between the ages of 15 and 44

Infant Mortality Rate (IMR) = the number of children out of every 1000 born alive who die before their 1st birthday

Life Expectancy (LE) = average age a person can expect to live to

Migration Rate = the difference between the number of immigrants and the number of emigrants per 100,000/1000 of the population per year 

Population density = the number of people per square kilometre (total pop. / size of area)

Natural change

• The change in population because of the difference between birth rate and death rate (not inc. changes due to migration)
• e.g. when birth rate > death rate, the population will grow naturally if the migration rate is zero
• e.g. when death rate > birth rate, the population will fall unless enough people migrate in

Zero growth rate

• When the population is neither increasing or decreasing