Total Fertility Rate
Introduced| English | Meaning |
|---|---|
| total fertility rate/ˈtəʊtl fɜːˈtɪlɪti reɪt/ | The average number of children a woman would have if she experienced the current age-specific fertility rates throughout her reproductive life. |
| replacement level/rɪˈpleɪsmənt ˈlevl/ | The TFR that keeps a population stable. |
How many children?
- Whether a nation's population grows or shrinks comes down to one number.
- That number is how many children the average woman has.
- Above a certain level, the population grows; below it, it shrinks.
- This key measure is the total fertility rate.
The total fertility rate
- The total fertility rate 总和生育率 (TFR) is the average number of children a woman has in her life.
- A high TFR means fast population growth.
- A low TFR means slow growth or decline.
- It is one of the most important numbers in population studies.

Total fertility rate compared with the replacement level 替代水平 of about 2.1 (illustrative countries)
The total fertility rate (TFR) is…
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The total fertility rate is the average number of children born to a woman over her life.
The replacement level
- The replacement level is the TFR that keeps a population stable.
- It is about 2.1 children per woman.
- Two children replace the two parents; the extra 0.1 allows for children who die young.
- At exactly replacement, each generation is the same size.
The replacement level TFR — where a population stays roughly stable — is about…
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A TFR of about 2.1 replaces the parents (plus a little for early deaths), keeping the population stable.
A TFR below 2.1 means the population will slowly ____.
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Below the replacement level, each generation is smaller, so the population shrinks.
Above and below replacement
- Above 2.1, the population grows — each generation is larger.
- Below 2.1, the population slowly shrinks and ages.
- As countries develop and educate women, TFR tends to fall.
- Many wealthy nations now have TFRs below replacement.
Growing, stable, or shrinking?
Sort each fertility rate by whether it is above, at, or below the replacement level of about 2.1.
Fertility rates tend to rise as countries develop and educate women.
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False. Education, healthcare and development strongly lower fertility rates: women marry later, use family planning and more children survive.
Select all true statements about total fertility rate.
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TFR measures births, not deaths. The other three are correct.
The replacement level is a little above two, not exactly two. It is about 2.1, because some children die before they grow up to have their own. In places with higher child mortality, the replacement level is even higher — you must more than replace the parents.
Why education lowers fertility:
- When girls stay in school and women can work, families tend to have fewer children.
- Better healthcare means more children survive, so parents choose to have fewer.
- Across the world, as development rises, the TFR falls — often from 5 or 6 down toward 2.
The total fertility rate (TFR) is the average number of children a woman has. The replacement level — about 2.1 — keeps a population stable. Above it the population grows; below it, the population shrinks. Development, education, and healthcare all tend to lower the TFR.