Normal hemoglobin levels vary based on age, sex, and overall health. For adult men, normal levels typically range from 13.8 to 17.2 g/dL, while for adult women, they range from 12.1 to 15.1 g/dL. Children have different normal ranges that change with age. Newborns, for example, have higher levels, which gradually decrease as they grow. It’s important to consult with a healthcare provider for specific ranges applicable to different age groups and individual health conditions.