Formulas and Definitions for Calculating Rates

Percent = __number of events__ X 100 total events

EXAMPLE:
Percent of people in County A over 50 in 2000 = _number of people in County A over 50_ X 100 total population of County A

numerator= number of people in County A over 50 = 150 denominator = total population of County A = 3,456 constant = 100 time period = 2000

Percent of people in County A over 50 in 2000 = _150_ X 100 = 4.3% 3,456

Crude Birth Rate (CBR) = ___number of live births during time period___ X 1,000 total population at mid-point of time period

EXAMPLE:
CBR for NM 2000 = __number of NM live births in 2000__ X 1,000 population of NM in 2000

numerator = number of NM live births in 2000 = 27,206 denominator = population of NM in 2000 = 1,819,046 constant = 1,000 time period = 2000

CBR for NM 2000 = __27,206__ X 1,000 = 14.9/ 1,000 population 1,819,046

Fertility Rate = __number of live births during time period__ X 1,000 total population of females age 15-44 at mid-point of time period
EXAMPLE:
Fertility Rate for Los Alamos County 2001 = __number of live births in Los Alamos in 2001__ X 1,000 population of Los Alamos females 15-44 in 2001

numerator = number of live births in Los Alamos in 2001 = 169 denominator = population of Los Alamos females 15-44 in 2001= 3,105 constant = 1,000 time period = 2001

Fertility Rate for Los Alamos County 2001 = __169__ X 1,000 = 54.4 /1,000 females ages 15-44 3,105

Crude Death Rate (CDR) =___number of deaths during time period____ X 100,000 total population at mid-point of time period
EXAMPLE:
CDR for Grant County 2001 = __number of deaths in Grant County in 2001_ X 100,000 total population Grant County 2001

numerator = number of deaths in Grant County in 2001 = 301 denominator = total population Grant County 2001 = 30,726 constant = 100,000 time period = 2001

CDR for Grant County 2001 = __301__ X 100,000 = 979.6/ 100,000 population 30,726

Age-specific Death Rate = __number of deaths among persons of a given age group__ X 100,000 population of persons in given age group at mid-point of time period
EXAMPLE:
Death Rate for ages 45-54 in = number of deaths among ages 45-54 in Bernalillo County
Bernalillo County 2001 __________________in 2001______________________ X 100,000 number of persons ages 45-54 in Bernalillo County in 2001 numerator = number of deaths among ages 45-54 in Bernalillo