Revised 24 May 2019


The crude birth rate (b) is the ratio of births over one year per 1,000 people within a population. A high present-day crude birth rate is in the order of 50 births per 1,000 people per year. Pre-historic crude birth rates are thought to have been around 40 to 50 births per 1,000 people per year. The crude death rate (d) is the total deaths at all ages per 1,000 people per year. There is no upper limit on the crude death rate as war, disease, and pestilence take their toll. However, because we are all mortal, there is a lower limit. With our present-day way of life with sound nutrition and medical care, a low crude death rate is in the order of 5 deaths per 1,000 people per year. Figure 2 below shows the world crude birth and death rates from 1960 to 2016.


Figure 2: World Crude Birth & Death Rates 1960 to 2016 (Data: United Nations 2019)


With improvements in medical care and nutrition there was a simultaneous sharp decline in the crude death rate and sharp increase in the crude birth rate until 1965 which resulted in a population boom. From 1965 onwards both the crude birth and death rates declined in tandem with the crude birth rate declining more rapidly.