This paper presents an updated 1-D radiative-convective, cloud-free climate model to estimate the habitable zones (HZs) around main-sequence stars. The new model uses updated absorption coefficients from HITRAN 2008 and HITEMP 2010 databases, which improve the accuracy of the previous Kasting et al. (1993) model. The inner edge of the HZ, determined by water loss, is estimated to be at 0.99 AU, and the outer edge, determined by the maximum greenhouse effect of a CO$_2$ atmosphere, is estimated to be at 1.70 AU. These estimates suggest that the Earth lies near the inner edge of its HZ. The model also considers the effects of stellar effective temperatures and planetary masses on HZ boundaries, and discusses the implications for current exoplanet surveys and future missions. The authors propose using stellar flux incident on a planet instead of equilibrium temperature to assess habitability, as it removes the dependence on planetary albedo. The paper includes a validation of the model using a well-tested 1-D line-by-line radiative transfer model, SMART, and compares the results with published studies. The updated model provides a more accurate estimate of HZ boundaries and highlights the importance of considering cloud effects in future studies.This paper presents an updated 1-D radiative-convective, cloud-free climate model to estimate the habitable zones (HZs) around main-sequence stars. The new model uses updated absorption coefficients from HITRAN 2008 and HITEMP 2010 databases, which improve the accuracy of the previous Kasting et al. (1993) model. The inner edge of the HZ, determined by water loss, is estimated to be at 0.99 AU, and the outer edge, determined by the maximum greenhouse effect of a CO$_2$ atmosphere, is estimated to be at 1.70 AU. These estimates suggest that the Earth lies near the inner edge of its HZ. The model also considers the effects of stellar effective temperatures and planetary masses on HZ boundaries, and discusses the implications for current exoplanet surveys and future missions. The authors propose using stellar flux incident on a planet instead of equilibrium temperature to assess habitability, as it removes the dependence on planetary albedo. The paper includes a validation of the model using a well-tested 1-D line-by-line radiative transfer model, SMART, and compares the results with published studies. The updated model provides a more accurate estimate of HZ boundaries and highlights the importance of considering cloud effects in future studies.