Crude birth rate is the childbirths per 1,000 people each year. This is a common measure of fertility for a given population. Crude birth rate is frequently used in population geography and demography and is a useful indicator in studies of population around the world. The crude birth rate could be of concern for particular countries who may be experiencing population decline or for national governments who are worried about population growth rates that are higher than their country can sustain.
The crude birth rate (CBR) is equal to the number of live births (b) in a year divided by the total midyear population (p), with the ratio multiplied by 1,000 to arrive at the number of births per 1,000 people.
The formula for crude birth rate is: CBR = (b/p)*1,000.
For example, in 2007, there were 3,250 births in a city with population of 223,000. Therefore: CBR = (3,250/223,000)*1,000 or CBR = 14.57. So, there were 14.57 births for every 1,000 people in the city.
The crude birth rate is considered "crude" because is ignores the age structure of the population and it doesn't take into account who among the population were actually able to give birth.