OBJECTIVES: Traditional life tables provide valuable insights into mortality patterns but need to be adapted for quantifying the benefits of medical interventions. This article presents a methodology that modifies life tables using relative risk data to estimate incremental changes in life expectancy. METHODS: We developed a calculator that applies this approach, allowing users to input risk-factor data with and without intervention to generate adjusted life expectancy estimates. The calculations to modify life-expectancy were based on estimating 'effective age', a concept widely used in risk communication studies. RESULTS: The calculator provides a structured approach for estimating life expectancy changes that can be used for health economic evaluations. Its user-friendly interface offers policy makers and researchers a framework to explore intervention outcomes. CONCLUSIONS: By incorporating relative risk data into life tables, this methodology supports a structured but simplified assessment of how medical interventions may influence life expectancy.