Replacement rate

Replacement rates

Replacement fertility is the total fertility rate at which women give birth to enough babies to sustain population levels, assuming that mortality rates remain constant and net migration is zero. If replacement level fertility is sustained over a sufficiently long period, each generation will exactly replace itself. In 2003, the replacement fertility rate was 2.1 births per female for most developed countries (2.1 in the UK, for example), but could be as high as 3.5 in undeveloped countries because of higher mortality rates, especially child mortality. The global average for the replacement total fertility rate, eventually leading to a stable global population, for 2010–2015, was 2.3 children per female.