A new climate model has been developed to estimate the habitable zones (HZs) around main-sequence stars, improving upon previous models by incorporating updated absorption coefficients for water and carbon dioxide. The model uses 1-D radiative-convective, cloud-free climate simulations and accounts for recent advancements in line-by-line databases like HITRAN 2008 and HITEMP 2010. The new model provides more accurate HZ boundaries, with the inner edge at 0.99 AU and the outer edge at 1.70 AU for our Solar System, suggesting Earth lies near the inner edge of the HZ. These estimates are applicable to a range of stellar types, including F, G, K, and M stars. The model also considers the effects of clouds, though it does not include radiative effects of clouds, which could extend HZ boundaries further. The study highlights the importance of using stellar flux rather than equilibrium temperature for assessing habitability, as it accounts for variations in planetary albedo. The results suggest that current exoplanet surveys should use conservative HZ estimates to ensure future missions are adequately sized. The model's findings have implications for ongoing and future planet searches, particularly around M dwarfs, where HZs are closer to the star. The study also addresses the limitations of previous models, including outdated absorption coefficients and the impact of collision-induced absorption. The new model provides a more comprehensive understanding of HZ boundaries, which is crucial for identifying potentially habitable planets in the universe.A new climate model has been developed to estimate the habitable zones (HZs) around main-sequence stars, improving upon previous models by incorporating updated absorption coefficients for water and carbon dioxide. The model uses 1-D radiative-convective, cloud-free climate simulations and accounts for recent advancements in line-by-line databases like HITRAN 2008 and HITEMP 2010. The new model provides more accurate HZ boundaries, with the inner edge at 0.99 AU and the outer edge at 1.70 AU for our Solar System, suggesting Earth lies near the inner edge of the HZ. These estimates are applicable to a range of stellar types, including F, G, K, and M stars. The model also considers the effects of clouds, though it does not include radiative effects of clouds, which could extend HZ boundaries further. The study highlights the importance of using stellar flux rather than equilibrium temperature for assessing habitability, as it accounts for variations in planetary albedo. The results suggest that current exoplanet surveys should use conservative HZ estimates to ensure future missions are adequately sized. The model's findings have implications for ongoing and future planet searches, particularly around M dwarfs, where HZs are closer to the star. The study also addresses the limitations of previous models, including outdated absorption coefficients and the impact of collision-induced absorption. The new model provides a more comprehensive understanding of HZ boundaries, which is crucial for identifying potentially habitable planets in the universe.