Birth rate is -
Fertility 

By fertility is meant the actual bearing of children.
A woman's reproductive period is roughly from 15 to 45 years - a period of 30 years.
Measurement of fertility are :-


Birth rate   
General fertility rate (GFR) 
General marital fertility rate (GMFR) 
Age specific fertility rate (ASFR)    
Age specific marital fertility rate (ASMFR) 
Total fertility rate (TFR)    
Total marital fertility rate (TMFR)
Gross reproduction rate (GRR)
Net reproduction rate (NRR)
Child woman ratio
Pregnancy rate
Abortion rate
Abortion ratio
Marriage rate

Birth rate

Birth rate defined as "the number of live birth per 1000 estimated mid yr. populations in a give yr."

Birth rate = Number of live birth during the year / Estimated mid year population x 1000
Live birth/1000 mid yr. population
Birth/1000 mid yr population
Live birth/10000 mid yr. population
Live birth/10,000 population of reproductive age group (15-45)