The development patterns of both historical and contemporary demographic transitions are essential in understanding the outcomes of age structure changes among the countries. Existing literature analyzing demographic transition as a precursor to population ageing does not classify countries or regions worldwide by the scale and dynamics of those processes. The aim of this paper is to identify and describe the differentiation of quantum and tempo effects of changes taking place during the demographic transition through classification of sub-regions and selected countries worldwide. The results of this research, based on the historical vital statistics starting from as far as 1736 and future projections until 2100, feature how sub-regions and selected countries in the world are differentiated in terms of the scale and dynamics of the demographic transition process. The analysis reveals the fact that majority of sub-regions in the world tend(ed) to undergo long transitions lasting over 70 years, though contemporary demographic transitions demonstrate higher intensity and higher maximal rates of natural increase. African sub-regions are expected to experience relatively long processes of declining birth and death rates and estimated to complete their demographic
transition in 90 years on average. The fastest processes, however, are observed in South America and Eastern Asia where some countries like China, for instance, completed their transitions in just 50 years. The scale and dynamics of demographic transition processes can serve as the ground for further research of challenges and development opportunities resulting from ageing societies during consequent post-transitional stages.