Pupil-teacher ratio (PTR)


Average number of pupils per teacher at a given level of education, based on headcounts of both pupils and teachers.

Data source

School registers, teacher records, school census or surveys for data on enrolment and teaching staff.

Calculation method

Divide the total number of pupils enrolled at the specified level of education by the number of teachers at the same level.

Data required

Number of pupils enrolled and teaching staff for the specific level of education.


A high pupil-teacher ratio suggests that each teacher has to be responsible for a large number of pupils. In other words, the higher the pupil/teacher ratio, the lower the relative access of pupils to teachers. It is generally assumed that a low pupil-teacher ratio signifies smaller classes, which enables the teacher to pay more attention to individual students, which may in the long run result in a better performance of the pupils.


This indicator does not take into account factors which could affect the quality of teaching/learning, such as differences in teachers’ qualifications, pedagogical training, experiences and status, teaching methods, teaching materials and variations in classroom conditions.


To measure the level of human resources input in terms of the number of teachers in relation to the size of the pupil population. The results can be compared with established national norms on the number of pupils per teacher for each level or type of education.

Quality standards

In computing and interpreting this indicator, one should take into account the existence of part-time teaching, school-shifts, multi-grade classes and other practices that may affect the precision and meaningfulness of pupil-teacher ratios. If feasible, the number of part-time teachers is to be converted to ‘full-time equivalent’ teachers; a double-shift teacher is to be counted twice, etc. Care should be exercised to include all staff involved in teaching. Teachers are defined as persons whose professional activity involves the transmitting of knowledge, attitudes and skills that are stipulated in a formal curriculum programme to students enrolled in a formal educational institution.

Types of disaggregation

By level of education and by type of institutions (private/public).