Page 38 - NIIÊN GIÁM THỐNG KÊ TỈNH HƯNG YÊN 2022

Total fertility rate (TFR)

Total fertility rate reflects the average number of live births that would
be born per woman during the childbirth period if the woman passes age-
specific fertility rates observed in a given reference period during the
reproductive period.

Formula by age group:

49 B
TFR   x

x 15 W x
Where:

TFR: Total fertility rate (children per woman);
B x: Number of live births registered in the year of women aged (x);
x : One-year age interval;

W x: Number of women aged (x) at the calculation mid-year.

Age specific fertility rates are accumulated from x = 15 to x = 49.
In fact, the total fertility rate is calculated by the abridged method. In case
the age specific fertility rates are calculated for 5-year age groups, index of

(i) represents the 5-years interval of age, such as 15-19, 20-24, ..., 45-49.
Formula by 5-year interval of age:

7 B
TFR  5  i
i 1  W i

Where:
TFR: Total fertility rate;

B i : Number of live births in the reference period of women in the age
group (i);
th
i: i age group;
th
W i: Number of women of the i age group up to the reference time-point.
The coefficient of 5 in the above formula is applied for the average rate
of consecutive 5-year age groups so that the TFR will be commensurate
with the age-specific fertility rates described in this formula.

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