This study aims to develop a way to estimate the maternal mortality rate (women per 100,000 who die during pregnancy, childbirth, or within 42 days) of past populations and describe the potential practical applications of such a measure. Using age-at-death data and maternal mortality rates for 76 countries from the United Nations database for the years 1990–1995, we examined the correlation between the rates and female-to-male death ratios during the childbearing ages (20–24 years). We utilized linear regression to determine an equation for calculating an estimated rate of maternal mortality from the ratio. Finally, we evaluated potential practical applications of the maternal mortality rate. We achieved a correlation of 0.894 (95% confidence interval, 0.837–0.932) between our dF20–24/dM20–24 ratio and actual maternal mortality rates. The rate can be compared with those of other past populations to identify relative differences in intra- and interpopulation maternal mortality. In the context of broader bioarchaeological information, such as indicators of care, nutritional deficiency, disease, and socioeconomic status, the estimated maternal mortality rate may offer exciting new insights into population dynamics, the causes of maternal mortality, sophistication of maternal care, and female experience of pregnancy and childbirth in past populations.