This indicator can be measured through a review of school register records. Review data on the enrollment, completion and repetition by grade level to determine which children have officially or unofficially stopped attending in the given school year. Depending on the availability of the data, you have 2 options for calculating the indicator.
Option 1: Data on the number of grade completers is available
If you are able to get reliable data on the number of successful completers, you can simply divide the number of dropouts (= all students minus completers) by the number of students enrolled at the beginning of the school year.
For example: (100 enrolled students minus 90 completers) divided by 100 enrolled students equals a 10% dropout rate.
Option 2: Only enrolment data is available
If you are only able to get reliable registration data from the beginning of the school year, then follow this calculation method: Number of students registered in the previous grade (last year) minus students entering a given grade (do not count repeaters) divided by the number of all students enrolled in the previous grade equals dropout rate.
For example, last year, 100 students were registered in Grade 7. This year, 95 students are registered in Grade 8, but 5 of them are repeating Grade 8 because they failed to complete it last year. This means 100 - (95 - 5) = 10 students who dropped out, divided by 100 students who were registered in Grade 7, which equals to a 10% dropout rate (10 / 100 = 10%).