The gross reproduction rate (GRR) is the average number of daughters that would be born to a woman (or a group of women) if she survived at least to the age of 45 and conformed to the age-specific fertility rate of a given year. It is often regarded as the extent to which the generation of daughters replaces the preceding generation of females.

This rate is similar to the net reproduction rate

Net reproduction rate

The net reproduction rate is the average number of daughters that would be born to a female if she passed through her lifetime conforming to the age-specific fertility and mortality rates of a given year. This rate is similar to the gross reproduction rate but takes into account that some females...

 but it ignores the fact that some women will die before completing their childbearing years. See also total fertility rate

Total Fertility Rate

The total fertility rate of a population is the average number of children that would be born to a woman over her lifetime if she were to experience the exact current age-specific fertility rates through her lifetime, and she...

 and replacement-level fertility

Sub-replacement fertility

Sub-replacement fertility is a total fertility rate that leads to each new generation being less populous than the previous one in a given area. In developed countries sub-replacement fertility is any rate below approximately 2.1 children born per woman, but the threshold can be as high as 3.4...

.

The GRR is particularly relevant where sex ratios are significantly affected by the use of reproductive technologies.