APES formulas

population dynamics

population growth rate (%)

[(b+i)-(d+e)]/total population * 100

Formula for the growth rate of a population. B+I= births + immigration, representing total gain. D+E = deaths + emigration, representing total loss. Multiply by 100 to get a percent.

birth rate

[(total births/total population)] * 100 (gives you a percent)

Not to be confused with crude birth rate.

death rate

[(total deaths/total population)] * 100 (gives you a percent)

Not to be confused with crude death rate.

crude birth rate

[(b/p)*1000]

Estimates the number of births for every 1000 people in a population.

crude death rate

[(d/p)*1000]

Estimates the number of deaths for every 1000 people in a population.

doubling time

Defined by the Rule of 70. Divide 70 by the growth rate to calculate.

For example: If the growth rate is 2%, then the doubling time is 70/2 so 35 years.

global population growth rate

(CBR-CDR)/10

Don’t confuse with the national population one!!

national population growth rate

[(CBR+immigration rate)-(CDR+emigration rate)]/10

Just do your best to memorize this and the global one. Remember - they are NOT the same!!

population density

population size/area

ts easy :)

percent change

(new-old)/old) * 100 —> to get the percent