By quantifying key life history parameters in populations, such as growth rate, longevity, and generation time, researchers and administrators can obtain valuable insights into population dynamics. Although point estimates of demographic parameters have been employed since the inception of demography as a scientific discipline, the construction of confidence intervals has typically relied on approximations through series expansions or computationally intensive techniques. This study introduces a novel method for accurately calculating confidence intervals for the aforementioned life history traits when individuals are unidentifiable and data are presented as a life table. These confidence intervals are determined by utilising the statistical properties of known life history trait estimates. The key finding is the accurate estimation of the confidence interval forr, the instantaneous growth rate, which is tested using Monte Carlo simulations with four arbitrary discrete distributions. In comparison to the bootstrap method, the proposed interval construction method proves more efficient, particularly for experiments with a total offspring size below 400. We discuss handling cases where data are organised in extended life tables or as a matrix of vital rates.