The number of out-of-school children can be expressed in several ways. This section draws largely on two indicators: the absolute number and rate of out-of-school children. The rate is the total number of out-of-school children as a percentage of all primary school-age children. It is useful for comparisons across countries and regions of different population size.

A total of 115 million primary school-age children were found to be out of school in the year 2001/02 as a result of the joint methodology.