Per wikipedia, what you are describing is the Net Reproduction Rate. TFR is not calculated that way. Instead, it takes women in the child bearing age group (sa

Per wikipedia, what you are describing is the Net Reproduction Rate. TFR is not calculated that way. Instead, it takes women in the child bearing age group (say 15-44 or 15-49), and adds up the age specific fertility rates to calculate the TFR. What TFR would result in replacement level of the population depends to some extent on mortality rates among women from birth to end of reproductive age, Thus advanced countries may achieve replacement levels at a TFR of 2.05 (say), while countries like India may do so at 2.1, and other countries with higher mortality may do so at 2.3+.