Between 2013 and 2023, the ratio of children to teachers in pre-primary education fell across most OECD countries, decreasing from an average of 15 children per teacher to 13. Despite this overall trend, a few OECD and partner countries experienced increases in child-to-teacher ratios, often due to rising enrolments and challenges in maintaining a sufficient teaching workforce.
In primary education, the average student-teacher ratio across OECD countries is 14:1. This is slightly higher than at lower and upper secondary levels, where the student-teacher ratio averages 13:1, although variation across countries at all levels of education remains significant.
Between 2013 and 2023, the OECD average class size at the primary level remained stable at 21 students per class. However, despite this overall stability, countries including Brazil, Lithuania, Mexico and the Republic of Türkiye experienced notable changes in class sizes, reflecting shifts in demographic trends and changes in education policies.
Education at a Glance 2025
Context
Class size and student-teacher ratio are two key indicators closely monitored by policy makers, as both have a significant impact on educational expenditure, particularly through the cost of teacher salaries. These metrics provide important insights into the allocation of resources within education systems and their potential influence on educational outcomes.
This chapter examines class sizes and student-teacher ratios across multiple educational levels, from early childhood education and care (ECEC) to upper secondary education. At each stage, the nature of teacher-student interactions evolves, reflecting differences in pedagogical approaches and developmental needs. In ECEC settings, for instance, the presence of additional staff such as teacher aides is common, supporting both instructional and caregiving roles. Similar support structures may exist at other educational levels, contributing to the overall learning environment.
In light of current challenges, including demographic shifts, teacher shortages and budget constraints, it is essential to closely monitor these indicators and their evolution over time. These factors influence both the quality of education and the ability of systems to meet the needs of students, requiring ongoing attention from policy makers.
1. Year of reference differs from 2013.
2. Year of reference differs from 2023.
3. Overestimation of student–staff ratios due to classification challenges between early childhood educational development and pre-primary education levels, as some staff classified under ECEC also teach in pre-primary classes.
For data, see Table D2.1. For a link to download the data, see Tables and Notes section.
Other findings
Child-to-staff ratios are generally lower for younger children in early childhood educational development services than in pre-primary education, averaging 9:1 across OECD countries. This reflects the greater need for close adult supervision in settings for children under the age of 3.
Differences in student-teacher ratios between general and vocational upper secondary programmes remained evident, with vocational tracks having higher ratios in 12 OECD countries.
Between 2013 and 2023, class sizes in public and private primary institutions have remained stable. In lower secondary education, class sizes in public schools also showed little change, while private institutions experienced a slight decrease.
Note
Student-teacher ratios and class sizes measure very different characteristics of the educational system. Student-teacher ratios compare the number of students to the number of teachers at a given level of education and in similar types of institutions. This indicator provides information on the level of teaching resources available in a country relative to its student population and serve as a pivotal indicator reflecting the human resources allocated, whether directly or indirectly, to children's education. This ratio is of importance from both administrative and economic standpoints as it is closely related to the amount of money spent per student.
In contrast, class sizes measure the average number of students that are grouped together in a classroom, which has greater significance from a psychological standpoint and is a more direct measure of the teaching resources brought to bear on a student’s development. At higher levels of education, students are often split into several different classes, depending on the subject area. This makes class sizes difficult to define and compare at these levels. Therefore, the indicator on class size is limited to primary and lower secondary education.
Staffing of early childhood education
Early childhood education and care (ECEC) profoundly influences children's educational, cognitive, behavioural and social development, both in the short and long term. As a foundational stage in lifelong learning and well-being, high-quality ECEC contributes to reducing inequalities and promoting inclusion from an early age. The quality of ECEC systems is influenced by a complex interplay of factors, including curriculum and pedagogy, staff education and training, workforce composition, staff-to-child ratios, and monitoring mechanisms at the system and setting level. These elements serve as key policy levers to enhance service quality and foster more equitable and inclusive environments (OECD, 2025[1]). Although no single indicator can fully reflect the complexity of the quality in ECEC and the interactions between children and staff, indicators such as workforce composition and staff-child ratios provide valuable insights into two essential dimensions of quality.
Type of staff working with young children
A diverse ECEC workforce plays a vital role in recognising and responding to the unique needs and strengths of children from varied cultural and individual backgrounds. It also provides children with exposure to adults with a range of profiles, experiences and expertise. In many countries, early childhood care is delivered by teams of professionals rather than a single educator managing an entire group, as is more typical in primary education (European Commission / EACEA / Eurydice, 2025[2]). These professionals often have different qualifications and levels of compensation, reflecting the variety of their responsibilities and the specific age groups they serve.
Staff who work directly and regularly as the principal contact with children in ECEC settings often hold titles that differ from traditional classroom teachers – such as pedagogues, educators, childcare practitioners, group-leading personnel or kindergarten teachers – reflecting national and institutional differences in ECEC systems. The minimum qualification requirements for these roles vary significantly depending on the ages of children they work with. In OECD countries, two-third of programmes serving children aged 3 and above require staff in these roles to hold at least a bachelor’s or master’s qualification. In contrast, only one-third of programmes for children under the age of 3 require personnel to have the same level of educational attainment (see Chapter B1, Box B1.1).
Although classroom teachers are traditionally regarded as the core practitioners in ECEC, there is growing recognition of the contributions made by auxiliary staff. The research literature highlights that assistant teachers or teachers’ aides play a crucial role in children’s development by facilitating learning, bridging gaps and providing caring support in various scenarios (Figueras-Daniel and Li, 2021[3]; Mowrey and Farran, 2021[4]; Webster and De Boer, 2019[5]). For instance, in Norway, kindergarten assistants engage directly with children, although they do not hold responsibility for providing educational content, which remains the domain of educational leaders. Similarly, in Japan, support staff play a key role in ensuring the smooth execution of teachers’ duties, contributing to the overall functioning of ECEC settings.
Teachers also benefit from the availability of support from other professional staff. The integration of specialised staff such as speech therapists, psychologists and school counsellors can enhance the overall effectiveness of early childhood teams by bringing targeted expertise to meet children’s diverse developmental needs. Through consultative guidance and tailored interventions, these professionals help promote more inclusive and responsive practices (European Commission / EACEA / Eurydice, 2025[2]; Fukkink and van Verseveld, 2020[6]). Moreover, teachers who experience supportive relationships with co-workers and supervisors report less stress and depression (Smith and Lawrence, 2019[7]). For instance, Lithuania employs a wide range of support personnel, including speech therapists, psychologists, art educators and swimming instructors, who contribute to both individualised support and group-based developmental activities. In Korea, kindergartens include special education teachers who adapt instruction to meet the individual needs of children. Ultimately, the composition of the ECEC workforce carries important policy implications not only for delivering high-quality education and care, but also for effective and sustainable human resource planning within the sector.
ECEC settings also rely on institution-level management personnel whose primary responsibilities include overseeing planning, supervision, co-ordination and overall administration. In practice, the boundaries between managerial and teaching roles may overlap when the ECEC setting is small. For example, teachers may assume administrative duties, while management staff may step into teaching roles when required. In Japan, for instance, vice principals in kindergartens support the principal in managing daily operations and, when necessary, assist directly in the care and education of young children.
Child-staff ratio and child-teacher ratio
The ratios of children to teachers and to contact staff both provide insight into staff intensity but capture different aspects of provision. The child-to-teacher ratio refers to the number of children per qualified teacher, while the child-to-contact-staff ratio covers all staff members who work directly with children, including both teachers and teachers’ aides. It is important to distinguish between the two, as they can lead to very different interpretations of staff availability in ECEC settings.
Developmental science highlights the importance of sensitive and individualised interactions between adults and young children, particularly in the early years of life. When staff-to-child ratios are lower and group sizes are smaller, educators can spend less time on managing group dynamics and more time engaging meaningfully with each child. These enriched interactions foster stronger, more supportive relationships, which are essential components of high-quality early childhood education. Higher interaction quality has been closely linked to improved outcomes in children's cognitive development, emotional regulation, and overall well-being (OECD, 2025[1]; OECD, 2021[8]; OECD, 2018[9]). Moreover, the benefits extend to staff as well: responsive educator-child relationships contribute to a more positive and sustainable work environment. In such settings, educators experience more stable and fulfilling professional relationships, which are associated with reduced staff turnover and greater continuity in children's care and learning experiences (COFACE, 2023[10]).
These benefits mean lower child-staff ratios are often associated with higher quality ECEC provision and for this reason are frequently subject to regulation. On average in OECD countries, there are 13 children for every teacher working in pre-primary education (ISCED 02) in 2023, with wide variations across countries. The ratio of children to teaching staff, excluding teachers’ aides, ranges from less than 5 children per teacher in New Zealand to 40 in Colombia (Table D2.1).
Some countries make extensive use of teachers’ aides. When counting all contact staff (teachers and teachers’ aides), child-to-contact staff ratios are significantly lower than the child-to-teacher ratios alone. For example, in the United Kingdom, the child-to-contact-staff ratio in pre-primary settings is 4, compared to a much higher child-to-teacher ratio of 32, due to the widespread use of teachers’ aides. Similarly, in Chile, pre-primary education relies heavily on teachers’ aides, resulting in a child-to-contact-staff ratio of 8, while the child-to-teacher ratio stands at 19 (Table D2.1). Maintaining low ratios can be difficult when resources are scarce or when the demand for early childhood education exceeds the supply of trained professionals. Nonetheless, countries that effectively incorporate teachers’ aides into the workforce are generally able to achieve much lower child-to-adult ratios, even when the number of qualified teachers is limited.
Lower child-staff ratios are particularly important for high-quality interactions with children under 3 (COFACE, 2023[10]). Child-to-teacher ratios in early childhood educational development services (ISCED 01) are consistently lower than those for pre-primary across all OECD and partner countries except Lithuania, Mexico, New Zealand, Peru and Romania. On average across OECD countries, there are 9 children for every teacher working in early childhood educational development services, ranging from 3 in Iceland to 62 in Peru (Table D2.1).
Differences in ratios are also observed between public and private providers. In pre-primary education, public institutions have slightly higher child-to-teacher ratios, averaging 15 children per teacher compared to 13 in private institutions. In early childhood education and development settings, this pattern is reversed: private institutions report 11 children per teacher on average, while public institutions report 8. These differences may reflect variations in regulation, funding structures and workforce composition between the public and private sectors (Table D2.1).
Trends in child-teacher ratios
Between 2013 and 2023, the ratio of children to teaching staff at pre-primary level fell from 15:1 to 13:1 on average in OECD countries. Most OECD and partner countries have seen a reduced ratio, with the drop being especially notable in Chile, China, India and Mexico, where the ratio fell by at least six children per teacher (Figure D2.1). In Chile, the significant improvement in child-to-teacher ratios can be attributed to substantial government investments in early childhood education including the expansion of public nurseries and kindergartens and the establishment of a dedicated undersecretariat for pre-primary education in 2015 (Castillo and Lobos, 2017[11]). These efforts aimed to reduce overcrowding and enhance staff-to-child ratios.
Improvements were also notable in early childhood educational development programmes across OECD countries, with the average ratio decreasing from 11:1 in 2013 to 9:1 in 2023. Mexico recorded the largest improvement, reducing its ratio by 24 children per teacher. Chile and Indonesia also made notable progress, each achieving reductions of at least five children per teacher (Table D2.1).
In contrast to the prevailing downward trend, the child-teacher ratio in pre-primary education increased by at least seven children per teacher in Colombia and Saudi Arabia between 2013 and 2022. This was a combined effect of both an increase in the number of children enrolled in pre-primary education and a fall in the number of teachers (Figure D2.1). The increase in student enrolment can be largely attributed to increased participation among children of pre-primary age during the period (see Table B1.2 in Chapter B1). In parallel, Saudi Arabia faces a significant challenge due to a shortage of qualified kindergarten teachers (OECD, 2020[12]).
Staffing of primary education
Primary school teachers play a pivotal role in children’s cognitive, emotional and social development (Jowett et al., 2023[13]; Rucinski, Brown and Downer, 2018[14]). In most OECD countries, primary school teachers typically teach several subjects to the same group of students, allowing for sustained interactions and stronger relational continuity. This daily proximity enables teachers to respond more effectively to individual learning needs and foster a supportive classroom climate. Lower student–teacher ratios in primary education can enhance these interactions by giving teachers more time and flexibility to engage with each student (Werler and Tahirsylaj, 2020[15]).
At primary level, there are 14 students for every teacher on average across OECD countries. In OECD and partner countries, the student-teacher ratio ranges from 8:1 in Greece to over 22:1 in Colombia, India, Mexico, Peru and South Africa. Across OECD countries, the student-teacher ratio at primary level experienced a general decrease from 2013 to 2023 with the exception of Austria, Latvia, Lithuania and Poland (Table D2.2).
Staffing of lower and upper secondary education
Teachers in lower secondary education often act as a bridge between the generalist approach of primary education and the subject specialisation of upper secondary levels. They support students during early adolescence, a critical period for social and emotional development, while introducing more structured academic expectations. In some educational systems, lower secondary teachers are trained to teach multiple subjects and maintain continuous interactions with a consistent group of students, which can help strengthen teacher–student relationships and provide stability as students adapt to more complex school environments. Recent research has shown that such sustained interactions contribute positively to students’ social participation and sense of belonging (Schürer, van Ophuysen and Marticke, 2025[16]).
Upper secondary teachers, in contrast, are typically subject specialists who work with older students preparing for higher education or the labour market. Their instructional role is more academic or vocational, depending on the educational track, and their relationships with students tend to be more formal and content focused. Given the segmented nature of upper secondary education – where teachers often see many different student groups each day – opportunities for individualised support are more limited. In this context, student-teacher ratios can influence the capacity of teachers to provide personalised guidance and monitor learning effectively.
At lower secondary level, the student-teacher ratio is about 13 students per teacher on average across OECD countries. It varies widely, from fewer than 9 students per teacher in countries like Croatia, Greece and Norway to more than 30 students per teacher in Mexico. At upper secondary level, the student-teacher ratio is also about 13 students per teacher on average. Despite this overall similarity, notable differences emerge when comparing the ratios between lower and upper secondary education within individual countries. In 12 OECD countries, the student-teacher ratio is higher at upper secondary level – for example, Finland has 8 more students per teacher in upper secondary education. In contrast, 14 OECD countries show lower ratios at this level, such as Mexico where there are 9 fewer students per teacher in upper secondary education. Despite these variations, Finland's ratio at upper secondary level remains lower than Mexico's, reflecting differences in national contexts, including how education systems are structured, differences in population density and school size, teacher workforce availability, policy priorities, and the level of public investment in education (Figure D2.2).
1. Year of reference differs from 2023.
2. Upper secondary general programmes only.
3. Student-teacher ratios at upper secondary level include information from post-secondary non-tertiary education.
For data, see Table D2.2. For a link to download the data, see Tables and Notes section.
At upper secondary level, the student-teacher ratio can vary dramatically depending on the programme orientation. In 11 OECD countries, the ratio is higher in vocational programmes than in general ones. In Colombia, there are about 30 more students per teacher in vocational programmes than in general ones, while the difference is 9 more in Latvia, 6 more in Denmark and 5 more in New Zealand. In other OECD and partner countries, such as Brazil and Mexico, the difference is reversed: there are over eight more students per teacher in general programmes (Table D2.2).
Class size
Class size continues to be a key concern for schools, education authorities, policy makers and parents, and can influence school choice. Smaller classes are generally perceived as enabling teachers to provide more individualised attention, reduce the time they spend on classroom management and align their instruction better to students’ learning needs. While the overall evidence on the direct impact of class size on student performance remains mixed (OECD, 2016[17]), many systems continue to prioritise it as a policy lever to support teaching and learning, particularly for disadvantaged students.
In response to these concerns, countries have implemented a range of policies aimed at addressing class sizes, especially in contexts of educational disadvantage. In France, class sizes have been reduced in early primary education within schools located in priority education areas, as part of a broader effort to address educational inequality (Government of France, 2023[18]; DEPP, 2020[19]). Ireland has adopted similar measures through its Delivering Equality of Opportunity in Schools (DEIS) programme, which includes lower staffing ratios in schools serving disadvantaged communities (Government of Ireland, 2020[20]). These strategies reflect a shared policy rationale that smaller classes may help improve learning conditions and support equity, even where evidence on learning outcomes is not always conclusive.
Average class size in primary and lower secondary education
In OECD countries, the average class size at primary level is 21 students. Most countries, except Chile, Israel, Japan and the United Kingdom, have fewer than 25 students per class on average. At lower secondary level, the average class size is 23 students across OECD countries. Class sizes vary widely, from fewer than 20 students per class in OECD and partner countries like Croatia, Estonia, Finland, Latvia, Luxembourg and Poland to more than 30 students per class in Chile and Japan (Table D2.3).
The number of students per class tends to increase from primary to lower secondary education in most countries, particularly in Costa Rica where it increases by 14 students. In contrast, in Australia, Hungary and the United Kingdom, the number of students per class falls between these two levels of education (Table D2.3).
Trends in average class sizes
Over the past decade, many education systems have been influenced by two concurrent trends: a decline in the school-age population and an increasing teacher shortage (OECD, 2024[21]). While these dynamics may seem to offset each other – fewer students could imply reduced pressure on staffing – the reality is more complex. Many systems struggle to recruit and retain qualified teachers, particularly in rural areas or for specific subjects, limiting their flexibility to adjust class sizes (OECD, 2024[22]). At the same time, budgetary constraints and rigid staffing formulas further complicate matters (OECD, 2020[23]). Moreover, despite falling enrolment in many systems, growing expectations for inclusive education, personalised learning and student well-being continue to increase demand for teaching personnel. As a result, average class sizes have remained stable or even risen in specific contexts.
Between 2013 and 2023, average class sizes remained relatively stable at both primary and lower secondary levels across OECD countries, although there were significant changes in individual OECD and partner countries. At primary level, average class sizes reduced by three students in Brazil and increased by three students in Lithuania and Mexico (Figure D2.3). At lower secondary level, the change in some countries is even more striking, where the average class size fell by seven students in Korea and increased by four in the United Kingdom between 2013 and 2023 (Table D2.3).
1. Year of reference differs from 2023.
2. Year of reference differs from 2013.
For data, see Table D2.3. For a link to download the data, see Tables and Notes section.
Similarly, class sizes remained steady in both public and private primary institutions from 2013 to 2023 on average across the OECD, while individual countries experienced significant changes. For example, in Latvia, both public and private institutions had among the lowest average class sizes in 2013. However, by 2023 private institutions in Latvia saw a substantial increase from 8 to 13 students per class, while student teacher-ratio in public institutions remained broadly stable. A similar trend was observed in the United Kingdom, where the average class size in private primary schools rose from 18 to 25 students between 2013 to 2023, while those in public ones remained stable. In contrast, Türkiye experienced decreases in both cases over the same period: public schools saw a slight decline from 23 to 22 students per class, while private schools experienced a more substantial drop, from 20 to 11 students per class. This reduction in class size during the period likely reflects increased investment in school infrastructure and education personnel. (Table D2.3).
Early childhood education (ECE): ECEC services in adherence with the criteria defined in the ISCED 2011 classification (see ISCED 01 and 02 definitions) are considered early childhood education programmes and are therefore referred to as ECE in this chapter. Therefore, the term ECE excludes programmes that do not meet the ISCED 2011 criteria.
Teachers’ aides and teaching/research assistants include personnel or students who support teachers in providing instruction to students.
Teaching staff refers to personnel directly involved in teaching to students. The classification includes classroom teachers, special-education teachers and other teachers who work with a whole class of students in a classroom, in small groups in a resource room, or in one-to-one teaching situations inside or outside a regular class.
Class size is defined as the number of students who are following a common course of study, based on the highest number of common courses (usually compulsory studies), and excluding teaching in subgroups.
The ratio of students to teaching staff is obtained by dividing the number of full-time equivalent students at a given level of education by the number of full-time equivalent teachers at that level and in similar types of institutions. Exceptionally, for early childhood educational development (ISCED 01) and pre-primary education (ISCED 02), this ratio is based on headcounts of students and full-time equivalent teachers due to the complexities arising from the lack of standardized study load criteria, variability in full-time enrolment hours, and the absence of a universally accepted FTE calculation methodology.
For the ratio of students to teachers to be meaningful, consistent coverage of personnel and enrolment data are needed. For instance, if teachers in religious schools are not reported in the personnel data, then students in those schools must also be excluded.
Class size is calculated by dividing the number of students enrolled by the number of classes. In order to ensure comparability among countries, special needs programmes are excluded. Data include only regular programmes at primary and lower secondary levels of education, and exclude teaching in subgroups outside the regular classroom setting.
Data refer to the reference year 2023 (school year 2022/23) and are based on the UNESCO-UIS/OECD/Eurostat data collection on education statistics administered by the OECD in 2024/25. For more information see Education at a Glance 2025 Sources, Methodologies and Technical Notes (https://doi.org/10.1787/fcfaf2d1-en).
Data from Argentina, the People’s Republic of China, India, Indonesia, Saudi Arabia and South Africa are from the UNESCO Institute of Statistics (UIS).
References
[11] Castillo, F. and M. Lobos (2017), “Early child care education: Evidence from the new law in Chile”, Journal of Pedagogy, Vol. 8/1, pp. 121-135, https://doi.org/10.1515/jped-2017-0006.
[10] COFACE (2023), “High-quality early childhood education and care: Low children-to-staff ratio as a primary driver for children’s well-being and families’ engagement”, COFACE Thematic Note, COFACE Families Europe, https://coface-eu.org/wp-content/uploads/2023/12/COFACE_ECEC_ThematicNote-MAY-2023.pdf.
[19] DEPP (2020), Dédoublement des classes de CP en éducation prioritaire : exploitation des enquêtes auprès des enseignants après deux années de déploiement, https://archives-statistiques-depp.education.gouv.fr/Default/doc/SYRACUSE/45798/dedoublement-des-classes-de-cp-en-education-prioritaire-exploitation-des-enquetes-aupres-des-enseign.
[2] European Commission / EACEA / Eurydice (2025), Key Data on Early Childhood Education and Care in Europe - 2025, Publications Office of the European Union, Luxembourg, https://doi.org/10.2797/004435.
[3] Figueras-Daniel, A. and Z. Li (2021), “Evidence of support for dual language learners in a study of bilingual staffing patterns using the Classroom Assessment of Supports for Emergent Bilingual Acquisition (CASEBA)”, Early Childhood Research Quarterly, Vol. 54, pp. 271-285, https://doi.org/10.1016/j.ecresq.2020.09.011.
[6] Fukkink, R. and M. van Verseveld (2020), “Inclusive early childhood education and care: A longitudinal study into the growth of interprofessional collaboration”, Journal of Interprofessional Care, Vol. 34/3, pp. 362-372, https://doi.org/10.1080/13561820.2019.1650731.
[18] Government of France (2023), Dédoublement des classes de CP en éducation prioritaire, Ministère de l’Éducation nationale, https://www.education.gouv.fr/dedoublement-des-classes-de-cp-en-education-prioritaire-303210.
[20] Government of Ireland (2020), DEIS: Delivering Equality of Opportunity in Schools, Department of Education, https://www.gov.ie/en/department-of-education/policy-information/deis-delivering-equality-of-opportunity-in-schools/.
[13] Jowett, S. et al. (2023), “Teacher–student relationship quality as a barometer of teaching and learning effectiveness: Conceptualization and measurement”, British Journal of Educational Psychology, Vol. 93/3, pp. 842-861, https://doi.org/10.1111/bjep.12600.
[4] Mowrey, S. and D. Farran (2021), “Teaching teams: The roles of lead teachers, teaching assistants, and curriculum demand in pre-kindergarten instruction”, Early Childhood Education Journal, Vol. 50/8, pp. 1329-1341, https://doi.org/10.1007/s10643-021-01261-7.
[1] OECD (2025), Reducing Inequalities by Investing in Early Childhood Education and Care, Starting Strong, OECD Publishing, Paris, https://doi.org/10.1787/b78f8b25-en.
[22] OECD (2024), Education at a Glance 2024: OECD Indicators, OECD Publishing, Paris, https://doi.org/10.1787/c00cad36-en.
[21] OECD (2024), “How are demographic changes affecting education systems?”, Education Indicators in Focus, No. 87, OECD Publishing, Paris, https://doi.org/10.1787/158d4c5c-en.
[8] OECD (2021), Starting Strong VI: Supporting Meaningful Interactions in Early Childhood Education and Care, Starting Strong, OECD Publishing, Paris, https://doi.org/10.1787/f47a06ae-en.
[12] OECD (2020), Education in Saudi Arabia, Reviews of National Policies for Education, OECD Publishing, Paris, https://doi.org/10.1787/76df15a2-en.
[23] OECD (2020), TALIS 2018 Results (Volume II): Teachers and School Leaders as Valued Professionals, TALIS, OECD Publishing, Paris, https://doi.org/10.1787/19cf08df-en.
[9] OECD (2018), Engaging Young Children: Lessons from Research about Quality in Early Childhood Education and Care, Starting Strong, OECD Publishing, Paris, https://doi.org/10.1787/9789264085145-en.
[17] OECD (2016), PISA 2015 Results (Volume II): Policies and Practices for Successful Schools, PISA, OECD Publishing, Paris, https://doi.org/10.1787/9789264267510-en.
[14] Rucinski, C., J. Brown and J. Downer (2018), “Teacher–child relationships, classroom climate, and children’s social-emotional and academic development.”, Journal of Educational Psychology, Vol. 110/7, pp. 992-1004, https://doi.org/10.1037/edu0000240.
[16] Schürer, S., S. van Ophuysen and S. Marticke (2025), “Social participation in secondary school: The relation to teacher-student interaction, student characteristics and class-related variables”, Social Psychology of Education, Vol. 28/1, https://doi.org/10.1007/s11218-024-09992-2.
[7] Smith, S. and S. Lawrence (2019), “Early care and education teacher well-being: Associations with children’s experience, outcomes, and workplace conditions: A research-to-policy brief”, https://doi.org/10.7916/d8-ngw9-n011.
[5] Webster, R. and A. De Boer (2019), “Teaching assistants: Their role in the inclusion, education and achievement of pupils with special educational needs”, European Journal of Special Needs Education, Vol. 34/3, pp. 404-407, https://doi.org/10.1080/08856257.2019.1615746.
[15] Werler, T. and A. Tahirsylaj (2020), “Differences in teacher education programmes and their outcomes across Didaktik and curriculum traditions”, European Journal of Teacher Education, Vol. 45/2, pp. 154-172, https://doi.org/10.1080/02619768.2020.1827388.
To download the data for the figures and tables in this chapter, click StatLink above.
To access further data and/or other education indicators, please visit the OECD Data Explorer: https://data-explorer.oecd.org/.
Data cut-off for the print publication 13 June 2025. Please note that the Data Explorer contains the most recent data.
Table D2.1. Ratio of children to staff in early childhood education (ECE), by level of education and type of institution (2023)
1. Year of reference differs from 2013: 2014 for Denmark, Luxembourg, Mexico, New Zealand, United Kingdom, Bulgaria and Croatia; 2015 for India and Peru; and 2016 for Colombia and France.
2. Year of reference differs from 2023: 2022 for Colombia, Peru and Saudi Arabia; and 2018 for Indonesia.
Table D2.2. Ratio of students to teaching staff from primary to upper secondary education, by level of education (2023)
1. Year of reference differs from 2013: 2014 for Colombia, Denmark, Türkiye, Bulgaria, Croatia, Peru and Saudi Arabia; and 2016 for France.
2. Year of reference differs from 2023: 2022 for Colombia, Ireland, China, India, Peru, Saudi Arabia and South Africa; and 2018 for Indonesia.
3. Student-teacher ratios at upper secondary education includes information from post-secondary non-tertiary education.
4. Public institutions only.
Table D2.3. Average class size at primary and lower secondary education (2013 and 2023)
1. Year of reference differs from 2013: 2015 for Costa Rica, Sweden, Switzerland and Indonesia.
2. Year of reference differs from 2023: 2022 for Croatia and Peru.
a – category not applicable; b – break in series; d – contains data from another column; m – missing data; x – contained in another column (indicated in brackets). For further control codes, see the Reader’s Guide.
For further methodological information, see Education at a Glance 2025: Sources, Methodologies and Technical Notes (https://doi.org/10.1787/fcfaf2d1-en)
Note: See under Chapter D2 Tables for StatLink and for the notes related to this Table.
Note: See under Chapter D2 Tables for StatLink and for the notes related to this Table.
Note: See under Chapter D2 Tables for StatLink and for the notes related to this Table.