This study examines the influence of demographic changes on India's economic growth from 1999 to 2019, emphasizing the impact of the rising working-age population on state domestic product per capita and sectoral value-added. While the overall influence of the working-age population ratio and core working-age proportions on per capita economic growth is limited, a higher proportion of high-skilled workers and urban residents positively affects per capita output. Furthermore, our analysis highlights sector-specific effects, with particular significance observed in the industry sector, where the influence of the working-age population is most pronounced.