Although cross-national data on primary education are classified according to ISCED, the differences in starting and ending ages and the duration of programmes remain. It draws a basic global outline of starting ages and duration of primary school based on data for the 2001/02 school year. The top chart shows that in the majority of countries primary education starts at age 6 (119 countries) or 7 (47 countries). These countries are home to 61% and 34%, respectively, of the world’s children in this age group. The data thus show that 90% of countries make ages 6 and 7 the official starting ages for primary school and 95% of children live in these countries.

The global picture is more varied with respect to the duration of the primary cycle. As the bottom chart indicates, primary education ranges from three to eight years in duration. However, in 114 countries primary education lasts for six years. Another 29 countries have four-year programmes, 22 countries have seven-year programmes, and 19 countries have five-year cycles.